The fashion industry is in a state of emergency. This has been made clear not only by the mounting bankruptcies of big-name retailers, but also by the closure of beloved small businesses. These are brands that won’t bounce back.

Before the Modist, Noor Tagouri would spend as much as an hour a day browsing fashion e-commerce platforms, she said, just looking for something to wear.

A journalist and activist (and fashion enthusiast) in New York, Ms. Tagouri had grown accustomed to watching runway shows and mentally calculating whether she could make any of the looks work, often coming up short.

Then, at Istanbul Fashion Week in 2016, Ms. Tagouri met Ghizlan Guenez, an entrepreneur working on an idea for a website that sold modest clothing from luxury brands. Ms. Tagouri was captivated, and when Ms. Guenez introduced the Modist in 2017, she became a loyal customer.

“It was life changing,” Ms. Tagouri said. “I actually really mean that.”

For Ms. Tagouri, who wears hijab, the Modist’s “effortlessly chic” styling ideas were just as important as its inventory of Valentino, Burberry and more. The images inspired her and made her feel proud.

“I had never known of a marketplace or a store where I could wear every single thing, and I didn’t have to think about layering,” she said. “I don’t think anybody will understand that unless they’ve gone through the experience of seeing themselves fully represented for the first time.”

While the Modist was one of the first companies to sell modest options from multiple luxury brands, major e-commerce retailers began adopting the same strategy around the same time, adding full-coverage categories to their websites.

There was a boom in competition for luxury modest shoppers, and the Modist raised millions in funding from investors, including Farfetch. But platforms like Net-a-Porter had more money, name recognition and brands in stock. (Today Net-a-Porter’s Modest Edit, formerly known as its Ramadan Edit, is offered beside the Summer Shop and Kidswear.)

In early April, Ms. Guenez announced the end of the Modist, writing that the economic crisis catalyzed by the coronavirus “has left our young business vulnerable with no option but to cease operating.” Customers were crushed, and so were other Muslim female business owners, who were already feeling anxious about their futures.

Melanie Elturk, the founder of the online store Haute Hijab, paid tribute to Ms. Guenez as a mentor: “We all stand on your shoulders,” she posted on Instagram.

Ms. Elturk established her company a few years before the Modist. Still, she said, Ms. Guenez had been a “total titan of industry when it came to navigating the V.C. world and scaling your business. Even though she got onto the scene later than us in the modest fashion industry, she did it with such a bang.”

“I am so devastated for her and for all of us — those who wear hijab, those who don’t, those who just prefer to dress modestly,” Ms. Elturk said. “It was an incredible source for us to go to and feel great about the way we dress.”