Erin Fincher is having a reckoning—with her closet. In the nearly two years since the pandemic started, she has narrowed her social interactions, spent months holed up in leggings and sweatpants, had a baby and reassessed her priorities. As she looks ahead to the New Year and prepares to go back to the office a few times a week, she realizes that much of her pre-pandemic wardrobe no longer reflects her identity.

So she has filled three garbage bags with clothes and shoes to donate, and moved many other suits and high-heeled shoes into basement storage. She put away four black A-line dresses, at least a half-dozen Express blazers, and at least 10 button-down dress shirts.

“They were a person I used to put out into the world,” says Ms. Fincher, a graphic designer based in the Washington, D.C., area. “As I look at my clothing and weed things out, sometimes I question, ‘Who was I trying to be in the past and who do I want to be in the future?’ ”

After living for so long in sweatpants, some people are finding that their home closets—filled with suits, formal shoes, purses, blazers and belts—can feel like overstuffed relics from another life. Nearly three-quarters of respondents in a November survey by consumer research firm CivicScience of more than 4,200 U.S. adults said their closets contain many things they will never wear again. Only 15% said they want to leave their closets as-is.

Even Tim Gunn, the TV fashion mentor known for his tailored suits and coordinated pocket squares, says his style has shifted during the pandemic. He now reaches more for casual attire such as jeans or chinos paired with turtlenecks and a blazer, he says. “It’s hard after you experience the comfort trap to go back to clothes that constrain you,” says the co-host, along with model Heidi Klum, of “Making the Cut.” “I had an epiphany in how I want to present myself to the world,” he says.

The pandemic closet purge isn’t merely an exercise in swapping formal clothes for casual ones, stylists say. The purge feeds a desire to simplify during complicated, uncertain times. And it’s an acknowledgment that looks created in the before times often seem false or irrelevant now.

“During Covid, we had to live with ourselves for a long time, and so it gave us time to think, like ‘wait. What do we actually like?’ ” says Nashville-based stylist Payton Dale. “So many of us are walking around conveying this fake persona of what we think we’re supposed to be.”

Retreating into homes has blurred the boundaries of work, family and social life; clothing geared around those siloed identities no longer makes sense, she says. “Before, for women especially, it was, ‘Here’s your mom outfit. Here’s your office outfit. Here’s the event outfit,’ ” says Ms. Dale. “We were existing for other people and the roles we created.”

During the pandemic she started conducting what she calls “soul styling” sessions. She charges between $450 and $600 for three virtual one-hour sessions that involve discussion of personality, style idols, and a “mood board” of looks. Her business has doubled since the start of the pandemic, she says.

Professional organizers, stylists and secondhand clothing retailers say business is booming. Online thrift store thredUP Inc. says consumer requests for free “clean-out kits”—bags and shipping labels for consumers who want to clear their closets of clothing—were up 67% in the three months ended Sept. 30 compared with the same period last year.

Holiday parties, a resumption of some in-person office work, and increased socializing, even under the cloud of Omicron, has prompted more questions from clients about how they want to appear, says Ellen Delap, a certified professional organizer in Kingwood, Texas.

Closets these days are “like an archaeological dig,” she says. “It’s not just putting on clothes. It’s much more than that,” she says. Suits, belts, purses and formal attire often go to consignment or to storage, she says. “People are seeking a simpler way to get out the door.”

Washington, D.C.-based Current Boutique, a secondhand retailer, says it received more than 22,000 pieces of clothing from consignors in September and October this year—the highest amount owner Carmen Lopez has seen in over 15 years—compared with roughly 15,000 during those two months of 2020 and about 19,000 for the same period in 2019.

Many of the items people are discarding are more formal, fancier pieces. “There’s a feeling you don’t have to fit into what you’re ‘supposed’ to wear,” says Ms. Lopez.

In the last six months, Julia Elrod has pieced together a new look that she describes as “retro academic punk.” This winter, the senior program analyst in Brentwood, Md., foresees a life that gets her out of the house more: She will likely start heading back into the office four times a week, and hopes to get together more with friends and even go out on dates with her husband. None of the stay-at-home leggings and long sweaters appeal to her anymore.

Merely getting rid of a bunch of clothes “felt like a Band-Aid,” she says. She wanted not only to cull her closet but also to find clothes that better fit her new sense of self.

“Pandemic life kind of coincided with becoming a new mom and working from home and trying to figure out what’s really important in life,” she says. “I don’t want to be the person fussing over a giant wardrobe.”

Starting a year ago, she spent $450 on consulting sessions with Ms. Dale. She has pulled together six garbage bags stuffed with leggings, blazers and work pants that no longer fit and will donate them. One of her new favorite looks: an old Star Wars or rock concert T-shirt paired with a blazer and high-waisted jeans. She wore the outfit to dinner recently with a work friend.

“I felt like myself,” she says. “And like I could focus on what I was out for and not my clothes.”

Christopher Rim purged his closet of 14 Tom Ford suits and over 30 ties, giving them to friends and to his younger brother who works in finance. “I haven’t worn a suit since February of 2020,” says the 26-year-old founder of an education-consulting firm, who lives in Miami. He met recently with a client while wearing a T-shirt and jeans; his client wore the same. “In another time we would have both been wearing suits,” he says.

He feels more at ease without the fuss of matching a tie or polishing shoes or carrying a suit jacket. “A lot has changed. People are more relaxed and a little more casual and comfortable,” he says. “I think it’s a good thing.”

Anne Marie Chaker