Funnily I was just posting today online on a video commenting how 'the internet isn't fun anymore' to say that Urban (a forum I've been in since 2000) is the only consistently social place I post any more.
Social media has ceased to be social - you can't actually keep in touch with what your friends are up to because it's just algorithms pushing you stuff that has usually been carefully created by people who have the time and money to do that. As I have said a few times, I genuinely liked facebook and found it useful to keep up with disparate friend group (and I didn't have any friends or family who post infuriating shit, though must be said my dad's started going that way of recent years), but it started making 60% of my feed random crap, so it became useless.
I find tiktok does produce some genuinely interesting comment contributors - but oy, contributing anything meaningful to it feels like a massive undertaking. You can make text comments but I note they make the word limit very tight, presumably to encourage people to respond with videos, so it's only providing you content, but 'social' it aint. Instagram I can't see the point of - I tried to see if it would act as a replacement for FB (and I do post photos from holidays, day trips etc) but couldn't find anyone I know on there and it's basically like FB in terms of most of feed being algorithm-driven, the only difference is it constantly shows me the same stuff posted on different video/meme-ripping accounts so it's just FB but more repetitive.
I will also third that Mumsnet is a huge site a small corner of which consists transphobia or demented-bourgeoise-ness, and that it's funny how people will make a big thing of nutpicking the worst threads on there but not from, say PistonHeads, which I dare say has some mad or bigoted posts on it as well.