On a rainy Wednesday night in Brooklyn, after an introduction with a minimum of fanfare, Janeane Garofalo walked onstage at the Eastville Comedy Club and looked out at a dozen people so scattered that calling them a crowd seems like a stretch. She spotted one man by himself who had attended a show of hers a few days earlier and happily pointed him out.

Third on a bill filled with young unknowns, Garofalo, 57, settled into her set with supreme comfort, wandering into multiple tangents and digging into self-deprecation. “When someone tells me I can’t do something,” she said, holding the pause with precision timing honed over three and half decades of telling jokes, “I’m grateful.”

It was a humble setting to see one of the most consequential comics of the past half century. Garofalo is a pioneer and Generation X icon who for a few years, it was reasonable to argue, meant for stand-up what Kurt Cobain did for music. The only moment during the set that hinted at her legacy came when Garofalo walked out of the spotlight and into the audience. The couple in the front row, already laughing, sat up a little straighter.

Later in the set, she turned to her career. “The ’90s were good, but then it dipped,” Garofalo said, adding dryly that she now realized that comedy was not her forte. “You know what is? Filibustering.”

Janeane Garofalo performs constantly in New York on bills with other comics, though you might not know it because she has little to no public profile. She’s not on Twitter, Instagram or any social media. She has no website or podcast, hasn’t done a special in years and doesn’t even have a computer, smartphone or email address. She turned down interviews with me twice. If you want to see her perform — and I recommend it — you have to search her out and sit in the room with her. I periodically stumble across her in a show and it always comes as a happy surprise from another time, like discovering a storied zine that only a few people still knew existed.

As she made jokes about refusing to go to the doctor and her inability to apply herself, a cringeworthy thought occurred to me: Is this what not selling out looks like?

I always found that pejorative phrase ridiculous: Selling out. Isn’t that the goal? It never made sense to me that a band stunk as soon as it signed with a major label. Or that artists should be shamed for making money to pay the rent. But as the stigmatization of selling out has faded over the past few decades, so vanished from the conversation that you rarely hear it used without sarcasm, I confess that I miss it. Something useful has been lost.

In his shrewd new book “The Nineties,” Chuck Klosterman argues that nothing defined that decade more than the concept of selling out. To illustrate, he focuses on “Reality Bites,” now considered the quintessential Generation X movie. It also happens to feature Janeane Garofalo as a jaded eye-roller who delivers quips like “Evian is naïve spelled backwards.”

The movie centers on an aspiring filmmaker played by Winona Ryder who is pursued by a responsible corporate striver (Ben Stiller, the film’s director) and a caddish poet who hates the right things (Ethan Hawke). She chooses Hawke. Klosterman writes that while Hawke’s character seems irresponsible to boomers and toxic to millennials, he was the right choice for Generation X. For them, and only them, Klosterman argues, “an authentic jerk was preferable to a likable sellout.”

“Reality Bites” was released when I was in college, and most people I knew didn’t root for either of Winona Ryder’s options so much as against the movie, sensing a cynical attempt to capture the youth market, a major studio romanticizing indie credibility. Stiller screened it on campuses across the country, and at my school, he was received with hostility at the postshow Q. and A. One student questioned the filmmakers for mocking corporate greed while taking product-placement money from the Gap and R.J. Reynolds. Stiller bristled, saying it cost money to make a movie.

In promoting “Reality Bites,” Garofalo took a cannier approach. Appearing on “The Late Show With David Letterman,” she short-circuited complaints about hypocrisy by criticizing Universal Pictures for trying to market “Reality Bites” as a Generation X story. It’s not, she said, dismissing the term as a buzzword, which was how I saw it at the time, too, and telling the flummoxed Letterman that she was uncomfortable following the script mapped out with his producers for their conversation. She sold the movie perfectly by performing contempt for selling a movie.

The partnership between Stiller and Garofalo is an even better representation of the 1990s divide on selling out than “Reality Bites.” They dated briefly and worked together throughout the decade, starring on TV shows and appearing in movies, co-hosting the MTV Movie Awards and co-writing a self-help spoof, “Feel This Book.” Stiller was a bigger star, but Garofalo had more cachet. (On Entertainment Weekly’s 1997 list of the 50 Funniest People Alive, she came in 39th, five spots ahead of him.) While his fame has grown, her seismic significance to comedy has been forgotten enough to make a refresher necessary.

Just as the 1980s comedy boom was going bust, Garofalo — along with Colin Quinn, Dana Gould and Alan Gelfant — put on a show at a bookstore in Hollywood that became a weekly magnet for talented young stand-ups looking beyond conventional club comedy. Stiller performed there and used some of the comics on his breakthrough television series, “The Ben Stiller Show.” So did David Cross and Bob Odenkirk, who met through Garofalo and went on to make another sketch comedy landmark, “Mr. Show.”

This bookstore was one of the centers of a blossoming new comedy scene. Some called it alternative comedy, others balked at that term. The cool move was to embrace it ironically as Garofalo did in one of her early television appearances. When the host of “The Dennis Miller Show” made a joke about her Doc Martens, she deadpanned: “I’m the alternative queen.”

Garofalo didn’t just help shift the comedy scene away from clubs. Her style represented a sea change from the polished, tight and desperately relatable bits ready-made to translate into a sitcom or a late-night appearance. In jean shorts and tights, she inched stand-up closer to the eccentric solo show, where a sharply honed point of view mattered more than accessible setups and hard punch lines. Her humor leaned on stories and a political sensibility, refracted through a culturally savvy lens. She fiercely skewered the fashion industry for giving women body image issues and fashionistas later pushed back by putting her on worst-dressed lists. Her jokes scoffed at cliché (“I don’t even speak during sex for fear of sounding trite”), and she dropped references in televised sets that not everyone would get (Antigone, Sub Pop Records) and continually teased the crowd.

On her 1995 HBO half-hour, she walked onstage to applause that she immediately mocked: “You just did that because this is on television.” In the beloved “Larry Sanders Show” and the cult movie “Romy and Michele’s High School Reunion,” she played sarcastic (and now very meme-able) misanthropes, becoming the rare comic who represented something larger in the culture. Original writers for “Friends” and MTV’s “Daria” have cited Garofalo as an inspiration for characters for their shows. In his recent memoir “Comedy Comedy Comedy Drama,” Odenkirk argues that Garofalo’s early stand-up anticipated much of the ambitious work in our current scene. “Janeane was the spark of the big bang, of a comedy reinvention that still resonates.”

Whereas Stiller shifted into blockbuster movies in the 1990s, Garofalo ran into choppier waters in the mainstream in ways that now seem clearly sexist. Her stint at “Saturday Night Live” was chronicled in an infamous New York magazine piece that included scenes of Al Franken yelling at her, Adam Sandler giving her the silent treatment and a writer unleashing his wrath after she called a sketch sexist. She compared her treatment there to “fraternity hazing” and didn’t last a full season. When it came to the big screen, she dismissed her one major leading role, a female Cyrano in “The Truth About Cats and Dogs,” as “not my kind of movie.”

It’s hard to say if these experiences changed her view on establishment success or confirmed it. But at the end of the decade, in her book with Stiller, she gave this advice: “Being popular and well liked is not in your best interest,” before adding, “If you behave in a manner pleasing to most, then you are probably doing something wrong. The masses have never been arbiters of the sublime, and they often fail to recognize the truly great individual. Taking into account the public’s regrettable lack of taste, it is incumbent on you to not fit in.”

When The Times did a story on the new generation of alt comics in 1997, Stiller recalled that when Garofalo had a bit that killed, she would not repeat it out of fear of being hack. “It’s almost like she was going too far the other way, because she didn’t want to be accepted,” he said. Odenkirk hit similar notes discussing her in “We Killed,” an oral history about women in comedy: “Anything successful is something she’s not interested in,” he said. “That’s not a good thing in the long run.”

That may be true if the goal is conventional Hollywood success. But what if you actually believed the 1990s discourse about selling out? Or short of that, just internalized it? Then some skepticism about success makes sense. And why not? Only a fool thinks the funniest comics are the most popular or that deeply respected ones don’t remain obscure. Moreover, it’s entirely reasonable to look at the state of popular culture and just roll your eyes.

There has always been something off-putting about self-righteousness over selling out. Indie music snobs are easy to parody. And obsession with credibility can paralyze artists. “Nothing was more inadvertently detrimental to the Gen X psyche” than anxiety over selling out, Klosterman wrote, expressing a view darker than my own, so alert to cost that it gives short shrift to the benefits.

Though it can seem otherwise, the ’90s critique of selling out was not only used to sneer. Besides directing a bit of shame at product placement, the most valuable thing it did was provide a powerful vision of making it that didn’t rely on money and popularity. A close read of early issues of The Baffler, a small, influential journal that at its inception that decade was something of a think tank for the dangers of selling out, offered hints at a positive ideal. It could be found in zines, indie music labels, offline.

This utopian view of a culture independent of corporate interference was defiantly local, uncompromising and wary of fame. Today, when everyone is trying to go viral and artists are judged by the most soulless Internet metrics, the value of an alternative seems more important than ever. The current stand-up of Janeane Garofalo fits in nicely.

That doesn’t mean she sees it that way. Her current comedy is filled with self-deprecating jokes about her failures, flaws, projects that didn’t get picked up. After the ’90s, she helped start Air America, the influential liberal radio station that collapsed but not before giving early platforms to Rachel Maddow and Marc Maron. She has taken scores of acting jobs in film and television, but they have little bearing on the one constant: her stand-up, the rare form where you can have near total control over your art.

We live in an age of dumb demographic stereotypes. Millennials, we’re told, are entitled snowflakes and boomers are selfish egotists. Describing huge groups of people in a few traits is absurd, but that doesn’t mean those reductionist ideas don’t shape us. The water in which you swim matters. I was reminded of this at a birthday party for my daughter’s friend. A dad my age told me of being in a band in the ’90s that signed to a major label and how he still talks to his therapist about selling out. Back then I never identified with Generation X, but now I do. When I watch “Reality Bites” today, not only do I like it more, but I can find something to relate to in every character, too.

In movies and plays from the 1990s (“Clerks,” Eric Bogosian’s “subUrbia”), the slacker could be a goofy kind of hero. Compare that with the ethos today summed up by Bo Burnham in his special “Inside,” which features his song “Welcome to the Internet.” The refrain goes: “Apathy’s a tragedy and boredom is a crime/anything and everything all of the time.”

Garofalo’s stand-up always made apathy and boredom look cool, glamorous and, most important, sensible. About boomers, she joked: “They got married and worked hard so their kids didn’t have to, and guess what, we don’t.” There’s a performance in this, of course, since she has always worked hard, but the hustle and grind has never been her brand, to use a word she probably wouldn’t.

Garofalo isn’t that different today than she was three decades ago, less likely to skewer those who promulgate unrealistic body standards than to confess her own. Her hair is longer, more tangled, but her clothes remain darkly colored, rumpled. “I’m not ready for Eileen Fisher,” she said in characteristic deadpan. “I can’t cross that Rubicon.”

Her affect remains wry, offhanded; she walks onstage holding papers and uses references more highbrow than your typical joke slinger, but she is also often disarmingly personal and self-loathing.

The main impression you get from her act is of a restlessness that is physical, as she roams into the crowd, but also intellectual, as she repeatedly entertains new ideas, following them down rabbit holes even at the expense of the joke. There is a real excitement and unpredictability about her sets that can be captured only in live performance. She never tells a joke the same way twice. Her comedy always seems resolutely present, frequently vulnerable, challenging and delighting her audience in equal measure.

It would be easy to see Garofalo performing with comics half her age to a sparse Brooklyn crowd as a portrait of decline. But to my Generation X eyes, it looks like a kind of triumph.