ON a chilly, gray afternoon, what strikes shoppers in the Jimmy Choo’s store on rue Saint-Honoré in Paris aren’t the Avril stiletto shoes with Swarovski crystals that sell for €3,495 ($4,250) but rather the pair of crystal-encrusted Diamond black sneakers that are €100 more expensive.

The sneaker was launched two years ago, but it’s gained new relevance for a brand normally known for its 10-centimeter-high heels (3.9 inches).

No Cannes film festival, no Met Gala, no nights out, postponed wedding celebrations, and never-ending work-from-home meant the occasions to show off elegant stilettos were rare in 2020 (except if you’re Emily discovering life in Paris in a Netflix show).

“The elegant, evening high-heel segment is suffering much more than other shoe categories,” says Hortense Demay, accessories purchase director at Paris department store Galeries Lafayette. “This crisis is only amplifying some trends that were already around.”

Demand for designer shoes last year slid 21% globally compared to a 19% slump for the broader footwear market, according to data collected by Euromonitor International. The segment of the market was also growing at a slower pace in the five years before the coronavirus pandemic hit.

While Lyst, the world’s biggest fashion search platform, saw online searches for “heels” increase 33% in the fourth quarter of 2020 from the previous year, reps believe it had more to do with a desire for shorter mules, which saw a 47% increase, and the general move to online shopping during the pandemic. Stilettos were down 12% and heel boots saw a decline of 9% from the year before; sandal heels were up 21%. Searches for slippers were up 242%, and within that category searches for clogs were up 110%.

Even love-to-hate it Crocs has seen new life, with 2020 revenue climbing more than 12%, to $1.4 billion, a record high for the company.

“Brand such as Louboutin, Sergio Rossi, Jimmy Choo, Stuart Weitzman saw their sales for elegant shoes decrease” in 2020, said Stephanie Clairet, divisional merchandise manager for fashion accessories and shoes at Paris department store Printemps, via e-mail. “They’ve had to adapt to the market and develop sneakers and lower heels.”

The creative director of Jimmy Choo has acknowledged that her own habits have changed during the pandemic. “Lately my line of shoes is all trainers,” Sandra Choi said during a talk on the business of luxury with the Financial Times prior to the holidays. She expects shoes will focus more on functionality going forward: “I foresee that I want everything to be even more comfortable. I don’t think glamour needs to be just on heels.”

Department stores are adapting. Galeries Lafayette’s flagship store on boulevard Haussmann is renovating its shoe section and will make more room for sneakers this year, Ms. Demay says.

Sneakers are now “a bit like denim jeans, which speak to all generations and all styles,” says Jennifer Cuvillier, style creative director at LVMH’s high-end department store Le Bon Marche in Paris. “They’re part of the classic wardrobe.”

The changes afoot in the world of shoes that started before the pandemic with the appeal of athleisure and casual wear have only accelerated. Some luxury fashion brands have seized on this wave with the resounding success of Balenciaga’s $976 chunky Triple S sneakers and the $700-plus socks-meets-shoe Speed Trainer model that’s ubiquitous in the streets of the world’s fashion capitals.

And it’s not just sneakers. Jimmy Choo — beloved by Princess Diana and Carrie Bradshaw in the Sex and the City series of the 2000s (soon to be rebooted) — recently started a collaboration with outdoor brand Timberland. The all-over Swarovski crystal pair of boots, which retails at more than $5,000, “sold out immediately,” John Idol, chief executive officer of Capri Holdings Ltd., the parent company, said in a call with analysts. The Hawaii sneaker is also the company’s bestselling item, he said on Dec. 3 at the Morgan Stanley consumer and retail conference.

Capri Holdings Ltd. — a listed company with Versace and Michael Kors in its portfolio — is one of the few companies with a luxury footwear brand to report quarterly results. It’s had “some challenges with the dress footwear business, and that was before COVID. Really, the taste of many consumers is changing, and it’s much more casual in nature,” Idol said at the Morgan Stanley conference. Going after the luxury casual footwear market will allow Jimmy Choo to go from around $550 million in annual revenue to $1 billion, Mr. Idol predicted without clarifying when that target would be reached.

“The biggest advantage of the sneaker is that it makes the wearer look younger,” says Pierre Hardy, the shoe designer at Hermes International. “You can wear the most traditional clothes such as a fur coat and mix it with sneakers, and you’ll look 10 or 15 years younger. It’s unconscious, but that’s their strength.”

Yet some glamorous brands are still emerging despite the pandemic. Amina Muaddi, the eponymous brand of a Jordanian-Romanian designer, is hot right now thanks to a strong social media strategy, according to Galeries Lafayette’s Ms. Demay. Searches on Lyst for Muaddi were up 386% in the fourth quarter from the previous year, which the company attributes to its specialization in mules.

Kim Kardashian and Rihanna have endorsed her stilettos known for their widened base. Ms. Rihanna’s brand Fenty — owned by LVMH — struck a design partnership with Muaddi, signaling that it’s not all gloom and doom for fancy shoes. While Muaddi is finding popularity, its sales volume cannot be compared to that of other well-known and established designers, Ms. Demay adds. Muaddi didn’t reply when asked to comment on the outlook for the evening female shoe category.

Edgardo Osorio is the co-founder and creative director of Aquazzura, an Italian brand favored by Meghan Markle that’s known for its stilettos with a pineapple logo on their soles. He says revenue in 2020 was hit by lockdowns but its bestsellers are still heels, even though Aquazzura’s offerings go from sandals to cosy slippers. He says he’s hopeful for 2021. “There are two directions for fashion: There are things that you need and things that make you dream. And we’re in business of — especially right now — things that make you dream and make you happy.’’

Mr. Hardy, who’s designed footwear for Hermès for three decades, foresees an appetite for stilettos once “representation” opportunities such as red-carpet events return. But the wave behind the appeal for sneakers is deep, he says. So he expects the future to be hybrid, between casual and more formal, traditional footwear styles. “Fashion is linked to the history of luxury but also to streetwear now,” he adds. — Bloomberg