Swap the phones for newspapers and this is a subway photo from 1920.
A sociologist named Erving Goffman described exactly this in 1963. He called it civil inattention: the learned habit of acknowledging that a stranger exists, then pulling your attention back so you don't intrude on them. A quick glance, then you look away. In a space packed with people you will never see again, looking away is the courtesy.
It's the quiet contract that lets a few hundred strangers share a tight platform without friction. You signal "I see you, you're no threat, I won't bother you." Phones slotted neatly into that ritual. They are the most convincing prop anyone has ever had for performing it.
The newspaper did the same job for a century. Subway photos from the 1920s through the 1970s show entire rows of riders vanished behind broadsheets, every face covered, nobody speaking. Radio got blamed for ending conversation. So did the Walkman. So did the cheap paperback before either of them. Each new object inherited the same eulogy: this is the thing that finally isolated us.
Connection on a subway platform was always rare. Strangers waiting for a train kept to themselves long before anyone had a screen to disappear into. The phone's real footprint is at the dinner table and in the living room, the places where idle attention used to have nowhere to go and now always does.
The behavior in this photo is a hundred years old. The object in everyone's hands is the only part that keeps getting replaced.