I will start:
It was after I saw that it rebranded to “X”. Set my acc to private, logged out and deleted it from my phone over the course of a day.
I asked a similar question on Masto months before, and decided that it would be great to do it here.
When musk tweeted something about requiring users to provide their location, I bailed (I know he never followed through on this).
Worked out OK, because I had time to find most of the people I was following on other platforms. When he killed 3rd party clients I definitely would have rage quit had I not already left.
Basically any time a social media platform axes third party clients, I’m out. None of these people can make a decent app.