It just seems like they are unhappy with the algorithm, and like any customer for any service you can cancel service, say why you are canceling service, and move to alternatives especially when your concerns aren't addressed.
Then again, who cares one way or the other?
And yet they post on Bluesky and Mastodon. If it's about effort vs. impressions, leaving X doesn't sound like a rational decision.
Seems like they prefer those platforms and perhaps the algorithm works better for their goals. Maybe they'll grow users over time and it'll be better for the EFF on a post/engagement ratio. Maybe more engaging users are on those platforms? I'm not fan of Bluesky (interactions I've seen are racist and/or far-left lunatics or communists and other such water heads), but then again who cares where they post?