Bluesky has already missed the boat. Unless musk publicly sets fire to a kitten or something, the mass migration is over, and they missed it.
But would I be alright with it at it's current size/user make-up? Yeah totally. (but I'm also not paying for it...)
https://techcrunch.com/2023/07/05/bluesky-announces-its-8m-s...
The whole concept of federation is that most of the users are on other people's servers, so an ad-based solution isn't as obvious. They can't count on all those eyeballs being monetizable if they're serious about the AT protocol.
Personally, I believe a lot of people are just sick of social media in general. When Reddit started turning to garbage some 3-4 years back, I started looking for alternatives. Found none. Slowly used it less. By the time the recent drama hit, my usage of it was already almost 0, and dropped to 0. Took a peek at the alternatives, judged them to be a waste of time and attention, and that was it. The niche that Reddit filled is dead for me.