Not exactly a twitter user , what is tweetdeck?
The only thing that made twitter useable. No ads. You put your lists of people into columns, so you only saw exactly what you wanted to see. No algos trying to shove “you may like” stuff down your throat.
I use it for work reasons but I’m not paying for it, I’ll deal without and start digging into what needs can be fulfilled with mastodon. I stopped using it the first time it broke for a week due to elon and I thought it was over then.
No algo is the big one for me. Don’t have to worry about that with Mastodon. And the advanced interface of Mastodon is also pretty nice.
Why are people still on there? Twitter has been sold; the old management is never coming back. X is, almost explicitly at this point, a platform meant for crypto scammers and white supremacists, and that is not going to change. If you aren’t part of or adjacent to those groups, fucking leave it.
Niche communities that took years to built up and that I can’t find anywhere else. For example Esperanto speakers are quite active on Twitter. They also have their own Mastodon instance, but it is not the same. (I use both now)