carl_dr parent
Except the graph shows this was happening way before COVID. The internet and how that has changed how people relate is much more likely the reason.
One of the first things I did with the net was to connect with people to go out and party with. Amazing how that morphed into zombie doom scrolling, something I would never have predicted.
in my opinion the largest effect is how we build cities. Having to drive everywhere and the separation between commercial, residential and industrial areas of american cities is very clearly a driver of this isolation.