I had a Twitter account since 2009 and pretty much never used it. I got on there and got sick of political posts pretty fast in 2015 and gave up again. But then around 2 years ago I discovered some niche communities i liked a lot, basically the same stuff I participated in on reddit, but I was enjoying the Twitter style where accounts have a bit more personality. There's some good humor too, for instance NY Times Pitchbot is pretty funny. I enjoyed Cory Doctorow's posts.
I like the anonymity of reddit and lemmy but Twitter is more of a place where people have avatars that are actually their photos, maybe use their real names, post photos of themselves (now that I think of it, no clue why people think that's okay on twitter and not reddit, that's just how it is though) and I felt like I got to know people more. Once it was obvious what a pathetic shitshow Musk was going to turn it into, I quit without thinking twice. I miss some of the people and discussions on there, but fuck it, there's no way.
Reddit, I started in 2008 and have been back and forth with the site since then, at times basically on it half the day. It's been steadily growing worse, though. Still a prime way to waste time, sometimes slightly useful or productive, but I feel like the value of what I'd read and participate in on there has slipped over time. The ownership/admins kicking up their head and turning out to be giant dickweeds certainly wasn't cool, obviously. Reddit used to seem like a hip or beneficial company that just stayed out of everyone's way. So, fuck 'em. I miss some communities on there and I'm sure I'll not hear about some local events and things about games. It's not like "ended friendship with reddit! Lemmy is my new best friend!" though. I don't want to participate in reddit but if I was to say, look at some subs now and then without an account to see what's up in a town I'm visiting or something, whatever.