I would say there are a lot of factors. Lack of: money, energy/health, transportation/infrastructure, destinations, time etc.

Anecdotal, but I live in a very small town/village in the US, I'm close to a trail so I got a (weak/cheap+has gears) eBike and I didn't even have it for 4 months before the trail closed for renovations... and 6 months later it still is so I haven't left the house since then. Granted it was more of an activity/utility thing but it was still good mentally and I was still getting into it.

Also see something like Bowling Alone, you probably aren't going to be very social even at a sit-down restaurant as most people probably don't see it as a social thing (aside from maybe the main counter at a bar/diner and even that is subject to unreliable factors).