I always get a little sad when I read these as I just assume younger people don't have this trouble.

I think Covid did not help. It changed the nature of how we meet and interact with strangers even subconsciously. I find that even among my friends things are much more clique-y than they were 3 years ago. Like I am the periphery of several friend groups and don't really don't get invited to any casual hangs anymore because they whittled down their core groups to 8-10 people or whatever and those same 10 people do all the things together except the occasional big gathering for a birthday or whatever, whereas before they would intermingle more. Hopefully it passes.

Anyway the rest of the advice here seems good. I think you should start from your interests. Find book clubs if you like to read. Maybe grab those 2 friends and start going to pub quiz if you like that. I know it's tough though.