"They'll train an AI on my deeply-valuable thoughts" is the absolute least of my worries about having an account on Twitter.
It's more just about me not wanting to stay in the place I grew up after all my friends moved away, especially after a whole bunch of slightly terrible people moved in next door.
Very few people are switching to Bluesky so they don't have their data scraped for AI models. X has become a messy cesspool of spammy ads, toxic comments, and an owner intent on making it his personal echo chamber.
It's more just about me not wanting to stay in the place I grew up after all my friends moved away, especially after a whole bunch of slightly terrible people moved in next door.