I’m in Lemmy and Mastodon. I left Twitter for good about a week after the Tesla guy acquired it and made his first flex on the app. I don’t even remember what it was, but I didn’t want to be a part of his toy, and all he has done is prove me right over and over. I left Reddit within a couple days of the announcement that mobile app developers were getting screwed, and I’d essentially have to switch to the native app to use a full-featured Reddit. It seemed like a crappy thing to do since developers like LJ Dawson (Sync), the Relay person, etc are who really built Reddit since Reddit was slow to get into apps.
I use Discord but only because it’s what’s required for a gaming guild, and my dynasty fantasy baseball league uses it too. I have no interest in using it outside of that.
I’ve never really used Youtube, so I haven’t checked out Peertube. Likewise, I never really used Insta, so I haven’t looked that closely at Pixelfed. I’m considering Pixelfed since I’m a hobby photographer, but I share my pics on my personal website (I don’t care who sees them tbh, it’s fun for me) and on my FB. I can’t seem to shed FB with so many people I know using that to stay in touch and schedule events, and the Marketplace is leagues better than Craigslist.