As you weave a cart the size of Bermuda from the plant-based-meats section to the detergents aisle, you must work to avoid collision not merely with other shoppers of the civilian class but also with the overwhelming number of Instacart employees — independent contractors who are picking out ripe avocados at Wegmans for people doing something less combative on a Sunday.

Founded eight years ago by an Amazon alumnus, Instacart is an app-based grocery service that will deliver within two hours and sometimes as quickly as an hour. I had imagined that Instacart operated only in a small number of cities that were not heavily car-reliant — who else would need it?

But it turns out that Instacart is everywhere. I stopped counting the number of locations listed on the company’s website when I got to Timnath, Colo., population: 3,295.

Last spring, Pay Up, an organization of Instacart’s gig workers campaigning for better compensation, published a report titled, “Delivering Inequality.” Using 1,400 samples of data supplied by workers across the country, the study found that the average Instacart shopper makes just $7.66 an hour, once the costs of mileage and additional payroll tax are accounted for.

On a recent morning at the Whole Foods in Gowanus, Brooklyn, most of the other shoppers around were also professional grade and nearly all were young people of color. A bank of refrigerators in the front of the store contained full paper bags with the Amazon logo on them: You can now get whatever it is you buy at Whole Foods delivered to you via Amazon Prime.

Sociologists, beginning perhaps most prominently with Ray Oldenburg in the 1980s, in his book, “The Great Good Place,” have analyzed the importance of the “third place’’ in the urban world. Home is the first place, and work is the second place. But it is this additional realm, he argues, of informal sociality, that is so crucial to the maintenance of civic engagement and just civility.

Cafes, butcher shops, bakeries, gyms, bookstores and churches are all third places. In more recent years, another sociologist, Eric Klinenberg, has written about their position in the social infrastructure of cities, the “set of physical places and organizations that shape our interactions,” and that when neglected or lost, can foster a dangerous strain of isolation.