This is an honest question for people still using X/Twitter and yet complaining about it: why?

It's been obviously going downhill for a while and the reason has been obvious too. The leadership doesn't care about your concerns.

Why not stop using it or move to something else?

There are a bunch of alternatives out there and most people don't have a job that requires them to specifically use Twitter.

Unlike Facebook, where I know I have missed out on communities by not using it, I don't feel like I've ever lost anything by not using Twitter. Anything that goes viral on Twitter these days gets a bunch of mainstream news articles anyway.