In 2014, the management at a McDonald’s in Flushing, New York, sought to eject the elderly members of the Korean community who had made the store their regular meeting point for all-day chat sessions, apparently at the expense of seating for customers during peak hours. Police officers were summoned, boycotts were threatened. News of the spat went as far as Seoul before a local state assemblyman brokered a truce between the community and the franchise owner.

Read: American nostalgia on a bun

The episode triggered a host of skull sessions among urban sociologists about city resources, assimilation, demography, and the cultural differences between American and Korean treatment of the elderly. But, at heart, the story revealed that fast food fills a gap in our society. Nearly all of the McFlaneurs lived within two blocks of the store, while the local library was a mile away and the closest senior center was even farther, in the basement of a church. “It’s how we keep track of each other now,” one habitué told The New York Times of their hangout sessions. He added, “Everybody checks in at McDonald’s at least once a day, so we know they’re O.K.”

For America’s graying cohort, often sectioned off by age at places like senior centers, the dining room of a fast-food restaurant is a godsend. It’s a ready-made community center for intergenerational mingling. The cost of admission is low—the prices beckon those on fixed incomes—and crucially, the distance from home is often short. And that’s just one demographic.

In spite of the plastic seats, the harsh lighting, and in many cities, the semi-enforced time limits for diners, people of all sorts can sit and stay and stay and stay—at birthday parties, first dates, father-daughter breakfasts, Bible-study groups, teen hangs, and Shabbat dinners. Or at supervised visitations and meet-ups for recovering addicts. For those who crave the solace of a place to call home that is not home, a fast-food dining room offers it, with a side of fries.

On a moment’s notice, a restaurant can also become a low-stakes venue for high-stakes assembly. The McDonald’s on West Florissant in Ferguson, Missouri, is a typical-looking store. On a Sunday afternoon in the summer of 2015, it was offering respite from 97-degree Missouri heat and what must have been at least 95 percent Missouri humidity. About 30 people were inside, a mix of ages, mostly black, but also white, people in Cardinals hats, people talking on phones, people playing Vince Staples and Kendrick Lamar from small speakers at tables. If the crowd was bigger than normal for the time of day, it was because that Sunday was the one-year anniversary of the shooting death of Michael Brown a few blocks away; memorials and protests were taking place just outside, on the street.

Read: Eat food. All the time. Mostly junk.