Email became mostly centralized without any company buying thousands of independent email servers.

The same could (and probably will) happen with other federated services.

Yeah good luck meaningfully using a Lemmy instance with barely any users.

There’s a reason both Lemmy and Mastodon only really started taking off when the equivalent proprietary platforms drove users away - a service like this needs users to create content.

Also the guy you’re replying to is right, stuff like this already happened in the past; look at the centralization of email (which is also federated) for example.