Even if it is - the federated nature of things means you can just move somewhere else. If Spez buys Kbin.social and Elon buys Lemmy.world or whatever, you can pack your bags and go to the plethora of other instances.
Moving isn't pleasant - it never is - but it's easy enough to do. If people are spread out enough, you won't even notice a difference. I'm really hoping that the fediverse is the real Web3. Not the crypto nonsense... just people, talking to each other, away from corporate greed.
Speaking of - even Facebook is getting in on the fediverse. They're launching "Threads", which is a competitor to Mastodon - and it uses ActivityPub. The fact that one big tech company sees potential in this setup means that hopefully the fediverse will be okay for "normies" soon too.
Of course, I'm also speaking as a crotchety old guard... I joined Mastodon in 2017, and Lemmy in 2020. This is the moment I've wanted for a long time.