I think the scenario posited here is the worse possible one where we are still chronically online but on a dead internet while being fully and relentless surveilled.
"The Internet sucks. Get offline," is the battle cry of someone who likes Marvel movies and the book that Target has at the checkout line, or lives in one of about five cities in the USA.
I'm not joking: I'll bet that NO ONE at your local library cares that you're weird so long as you're polite and follow the rules.
As I said, this is something people who live in about five cities think. Congratulations on living in one of them for your entire life.
Most of us had to do something like look in the yellow pages for a martial arts school, discover there were none, and be sad. Hell, I live in one of the ten most populous cities in the USA, and there is literally zero chance to play squash because there are no facilities in the entire city.
I couldn't watch anime beyond Sailor Moon until I was 17 and went off to a summer camp at a university in a big city. My roommate happened to have loads of knowledge and a big collection, which he graciously shared with me. He'd, of course, acquired it all with the Internet. Something unavailable to me.
Now extrapolate for hobbies that don't require a physical space, where you can find others on the Internet, even if everyone in a hundred mile radius of you thinks that hobbit is for "queers."
I boulder, run, play tennis. I read about thirty books a year. I have lots of hobbies. But the Internet has made them better. I write novels. The people who help me with beta reading are online, because no one IRL is interested in what I write.
Again, expanding one's social circle.
Sincerely, your fellow terminally online HN commenter.
The joke about middle-of-nowhere towns is that the only thing for teens to do in meatspace is to go to the Walmart. Because there's nothing else to do.