You've isolated yourself from the world man, if it wasn't Internet it would've been something else. If you really don't want to be isolated you can change that right now.
In fact, I'll concede it is even possible that you have to work not to isolate yourself when, after dipping your toe into the internet, you trip into the rabbit hole.
One of the big problems is that we do care for the conversation on these forums (see also the classic "somebody is WRONG on the internet" xkcd), but we don't really care for each other. Relatively few of us end up actually meeting offline or ever establishing real relationships. So you get the illusion of socialization, but when the chips are down, nobody is going to care in your hour of need - which means you're indeed alone shouting into the void.
This was maybe less pronounced in the '90s, when internet groups were smaller and tighter. It's like sitting at some cafe on a small square talking to strangers - where in the past you'd be talking to the small cast of regulars, because the square was a bit hidden away from the main flow of people, but it has been since discovered by tourists, and now you're just chatting with passersby you'll never meet again, about topics you'll never do anything about.
I think that is a big assumption to make for someone we don't know well. I do believe some unique experiences can have a huge effect on individuals and other experiences might not replicate the same results.
I mean I don't think I'm that far out there, these activities cost a lot of mental energy and leaving my comfort zone, and I like to think that thanks to the pandemic, a lot more people have become OK with being at home.
Anyway yeah, the internet was my social life, it's where I met my live-in girlfriend, it's where I spend my spare time, it's fine for me.