Downtown Boston is trying to find its post-pandemic identity. It’s fighting an uphill battle.

Five years after COVID shut down Boston, things feel, by and large, normal again. There are lines at lunch spots, crowds at the Garden, college kids at the bars. But the city isn’t the same.

Measures of foot traffic and office vacancy haven’t fully rebounded. Hybrid work remains pretty common. Car traffic is worse. Empty storefronts persist.

But more than anything, we just don’t mix like we did before.

A Northeastern University study of cellphone data found that when COVID hit, inhabitants of Greater Boston became far less likely to interact with people of different socioeconomic backgrounds. Those numbers have been recovering, but for many parts of the region, particularly in the suburbs, levels of what researchers call “social exploration” have fallen sharply.

And that’s bad news for a city whose culture and economy have, for centuries, been built on people mixing, connecting, and sharing ideas, said Northeastern University physicist Esteban Moro, who’s leading the study. Bad enough that it raises questions about what cities like Boston are for, now, and how we make them places that people connect once again.

“Cities are these social engines that put together people,” Moro said. “This is the purpose of the city, right?”

These days, that engine isn’t working like it used to. Moro and his colleagues at Northeastern’s Social Urban Networks Group track the movement of people across cities, and when they look at Greater Boston they see, basically, less movement. Generally, people in the most affluent suburbs are staying in their affluent suburbs. People in the region’s lower income corners stay there, too.

It’s an indicator of the diminished role that downtown plays in the daily lives of Bostonians. According to recent figures from the Downtown Boston Alliance, about 20,000 fewer people work downtown than they did five years ago, and they come in, on average, about three fewer days per month. Add it up, and the work trips into the core of the city district have fallen by almost half.

It’s the sort of challenge Boston has faced before, said Karilyn Crockett, a former city director of economic policy and research who now teaches urban planning at MIT. In the 1950s and ‘60s, as residents decamped to the suburbs and jobs followed, Boston responded by constructing skyscrapers that signaled to the world that the city was a place for doing business. It’s time, Crockett said, to find a new signal.

“The fundamental thing that we’re asking is, where are people?” she said. “Where is the center of gravity in the city, whether for shopping or for hanging out or for work? Where do people come together?”

Increasingly, that’s neighborhoods where people do more than work. While foot traffic downtown remains below pre-pandemic levels, according to city data, it’s nearly back citywide, and up in places such as Fenway and Longwood. What’s the difference? Those “multipurpose” neighborhoods, as Moro describes them, provide chances to live, work, and play in more equal measure.

That’s something the Wu administration is trying to do downtown, offering a generous tax break to help convert underused older office buildings into housing. Mayor Michelle Wu said the city has received applications to convert 20 buildings into 760 units of housing, 153 of which will be income restricted.

“Every building that comes back to life makes a difference,” Wu said.

Even office buildings that aren’t being converted are seeing new life.

Take 63 Franklin St., an old bank headquarters in Downtown Crossing. In December, job-training nonprofit Breaktime paid $6.3 million to buy it to house 40-plus employees, a health clinic, and retail space where the teens Breaktime works with can hold jobs — showing how a downturn in office values can open new doors for new ideas.

The city’s trying other things too, like doling out $10 million in federal COVID relief funds to help 90 small businesses find a toehold in empty storefronts, and pushing Beacon Hill to provide 225 new liquor licenses, which it will distribute across the city to spur new restaurants in all corners of Boston.

But those efforts are fighting an uphill battle.

The pandemic accelerated a shift toward online shopping that was taking hold well before COVID, and the rise of takeout — in place of restaurant meals — has persisted, too, Moro’s data shows. Remote work and hybrid arrangements mean people congregate less often downtown, for both work and play.

People like Brenda Bond-Fortier, a professor in the Sawyer Business School at Suffolk University, who studies organizational change and has witnessed it herself in the wake of the pandemic.

Bond-Fortier used to spend her days downtown, at Suffolk. Today, she’s teaching her graduate classes online, from her home in southern New Hampshire, and ventures in just two days a week. She misses the bustle of Boston and seeing her colleagues, but she doesn’t miss spending 10 hours a week in the car.

“I’m very blessed where I have job with a bit more flexibility in terms of when I do and don’t go to the city,” she said.

To Crockett, even the word “downtown” feels a bit archaic, as it implies we’re all going to the same place. In this more splintered age, we aren’t.

“If people are going to venture out of their home for any reason,” she said, “it’s to have a particular experience.”

And experience is a big part of how developers aim to draw people out now. Food halls, for instance, are springing up across the city, not just catering to office workers seeking lunch but also tourists, families, and after-hours crowds into the night.

A slew of for-profit “Instagram museums” and immersive art experiences have recently taken up residence in hollowed-out storefronts. A Harry Potter exhibit has lately drawn throngs to an empty old Best Buy at the CambridgeSide mall. “Competitive socializing” is all the rage in the Seaport, where different venues offer mini-golf, ping pong, bowling, pickleball, or darts. And the recent arrival of new spaces where people can both shop and linger — be it at Beacon Hill Books & Cafe, or the batting-cage-boasting Dick’s House of Sport in Back Bay — are models for how businesses can transform an errand into an event.

Even small businesses are attempting to be a little bit of everything.

In the wake of the pandemic, Justin Sorbo and two colleagues left their longstanding jobs at gym chain Equinox to open Pearl Street Fitness training studio in the Financial District. The gym’s owner, David Cheal, purchased a former convenience store and renovated it into a boutique gym where customers can linger after workouts on tufted leather couches, sipping whiskey or getting a trim from one of the visiting barbers that pass through. His goal was to create a ”third space” for clients to hang out in, and to work from before or after sessions.

“The entire thing is to facilitate relationship-building of different kinds and having strong bonds and connections with people,” Sorbo said. “Normal face-to-face interactions are something that’s becoming sparse in the area of remote work. We’re definitely shooting for a tighter community here, and we do have that.”

But there’s a catch. All of these new places are private spaces, and many of them quite pricey.

That’s a challenge in a city that aspires to be for all of its people, said Ted Landsmark, director of Northeastern’s Dukakis Center for Urban and Regional Policy. Cities, after all, aren’t just blocks and buildings, but places where “joyful interactions” can bring people together.

“It’s incumbent on public leadership to encourage those kinds of informal interactions,” Landsmark said, “particularly around entertainment, shopping, play, and culture.”

That can take various forms, he said, from public art to public gatherings — both of which the Wu administration has experimented with — to lowering T fares on weekends to draw more young people downtown. It can mean ensuring that major developments include space for civic life — such as the popular new plaza atop the Massachusetts Turnpike at the Lyrik building. And it can mean making more of the public spaces Boston is fortunate to have, especially along Boston Harbor, where longstanding efforts to increase access still have a ways to go.

“Other cities have activated their waterfronts,” more than we have, Landsmark said. “We still tend to underutilize our location on the ocean.”

Boston’s waterfront is just one untapped resource. The city is also looking to increase access to its world-class cultural institutions, and attempting to find ways to make them feel more welcoming to people from across the city.

That’s the idea behind Boston Family Days, a program Wu launched in 2024 and expanded this year. It allows any family in Boston with children to visit any of nine museums on the first two Sundays of each month for free. Over 44,000 people participated in 2024, and 11,000 more have signed on this year.

“Every young person in the city deserves to feel at home in every part of our city,” Wu said.

Indeed, Wu said, we all know what cities need to thrive. Even kids. Every year, Wu meets with a kindergarten class at the Boston Society of Architects, and organizers ask the kids to design a model city. You might think they’d draw skyscrapers, Wu said, but the kids had other plans.

During a recent showcase, the mayor recalled, one child drew gigantic beds — so everyone would have a place to sleep — another designed a free ice cream store, and a third a massive owls’ nest. Why? So the owls can come out at night and catch all the rats.

“Even at a young age our kindergartners understand our cities have to be safe, beautiful, welcoming, and fun,” Wu said. “Especially now, when everything does feel so disjointed and isolated, people are looking for experiences to have together.”

That’s what cities have always been for. Before that week they shut down five years ago. And still today.

Yoohyun Jung and Catherine Carlock of the Globe staff contributed to this report.

Janelle Nanos can be reached at janelle.nanos@globe.com. Follow her @janellenanos.