“We’re in the middle of a very dynamic setting, which is accessible just by walking out the door,” said Connie Vance, 79. Three years ago, Ms. Vance, a retired nursing professor, sold her Westchester townhouse and moved with her husband, Ralph Kelley, a semiretired lawyer, to the Encore, a rental building in Lincoln Square.

“We loved the city and wanted less responsibility,” Ms. Vance said.

After two years in a one-bedroom, the couple moved a few floors up, to a two-bedroom, a very easy matter because, after all, they were dealing with a rental. The gym, the roof deck, the lobby — all great. “But we don’t have to maintain any of it,” Ms. Vance said. “It’s like living in a hotel.”

In some instances, the adult children of these new older New Yorkers also live in the city, along with the grandchildren. Such is the case with Mrs. Shaoul. Yet another reason to make the move.

“You get to see your children for dinner or just for coffee,” said Gary Malin, the president of the real estate brokerage Citi Habitats. “You don’t have to make elaborate plans to see each other as you would if you were still living in the suburbs. It can be spur of the moment.”

The city, always relatively easy to navigate, always hospitable to people well past the first flush of youth, has become even more so in the past decade, said Kathy Braddock, a managing director at the real estate agency William Raveis NYC. “Before, the outer boroughs were a little isolated,” she said. “But now you have Uber and Lyft.”

Access to the offerings of big-box stores is also no longer the sole province of suburbanites. “With the advent of Amazon, the need to live out of the city for those resources no longer exists,” Ms. Braddock said. “You combine that with advantages like joining a museum here for $100 a year and being invited to special parties for members — and as you get older, you can make do with a smaller place, because New York becomes your playground.”