If I didn't have work to go to, things would indeed be pretty dark, but that doesn't mean I'd prefer falling into a hole of substance abuse and tech addiction.
I can't speak what else all of them do, but one is a frequent source of information on free concerts and plays, local art exhibitions, and so on.
They'd seem to run counter to your idea of what people would do if they didn't have to work.
People do tons of work even when they’re not being told to, in my experience. It’s sometimes “worth” a ton less than the time they put into it, and they’re usually making little or no money at it, but that doesn’t make it not-work.
But yes, people do many things as hobbies that other people do as work.