Too late, at this point. Mastodon was never going to be the mainstream replacement, at least not anytime soon. Bluesky honestly took too long. Had it opened up first, people would have poured into it. But once they're settled in Threads, that's where they'll stay.
It is profoundly depressing to watch Musk crumble only for the internet to flock mindlessly back to Mark fucking Zuckerberg. Just when I was hopeful we might break away from these established giants...