In my opinion the big platforms jumped the shark long before they went live. Bad incentives, bad motivations, bad operators with bad intentions.
But to be tempting, the new platform would have to have no "algorithm" or machine-personalized feed, no tracking, no genAI presence, and most of my friends.
Personally I would really enjoy something that looks like Instagram but is focused on photos instead of images with senseless motion, pictures in text, and loose all the woman advertising their onlyfans. It's downright annoying that Instagram always puts up a picture from my one cosplayer/alt-fashion model IRL friend doing something outrageous because if it wasn't for that I would show people photos I take on the Instagram app on my phone.
I lost my Facebook account because they suspended me for "integrity issues". I tried and failed to appeal successfully. I was pissed at first because I had had that account for over a decade, but after some months, I was glad to have lost it.
I don't use Instagram.
I only use Twitter now.
Reddit on read-only mode.
WhatsApp to talk to people since everyone and their mom is on it. But I'm considering taking a long break from it and seeing if I survive.
Hacker News actively.
I'm not sure what it would take for me to join another social media platform because they do nothing for me if it's just scrolling through pictures and videos.
I love devouring useful information, though, hence my love my HN. So I guess, if a new social media platform comes out that's centered on intellectual conversations (anything that gratifies intellectual curiosity) I'd sign up.
Sometimes I think about how I'd need Meta services if I ever start a business, and I hate that thought.
people running it rather than the investor class
something that learns from and builds on AP & AT ideas, but makes permissions and privacy core to the open protocol from the start