We are decentralized, according to FediDB, the Fediverse has 14.2 million accounts. Lemmy+Piefed+Mbin have 551k users. Obviously we could be better spread out, but the fact that there's no instance at 50% share is already pretty nice.

And if a big instance enshittified, it would be drastically easier for everyone to leave it compared to convincing people to leave Reddit or something. You just export/import your user settings and you get to keep the communities you've subscribed to and block, and the users you've blocked.