While I don't agree with you, there is an interesting discussion to be had here about digital "commons" (something like the "public utility" concept in the US), I think.
If a company with a near-monopolistic network effect (Google, FB, etc.) censors speech or who-can-talk-to-who/see-what on their platform, it seems that most folks agree that this is bad, whether or not they're willing to do anything about it.
So, instead, we have decentralized services (and semi-decentralized ones, like Mastodon). At what point does a Mastodon community operator's decision to censor speech or who-can-talk-to-who/see-what on their platform become problematic? When a community achieves a large size? If new community members aren't made aware of the censorship? Is the difference between these communities and an ultra-ubiquitous one like "having a Google account" or "being connected to friends on Facebook" a difference of degree, or a qualitative one?
It's simple to argue an extremist position of "all speech between any set of parties must not be suppressed for any reason, even by the parties themselves", but I don't think most people want to live in that world. Similarly, it's pretty hard to isolate a line past which an operator of a community-service should be held to a different standard of conduct because of how ubiquitous/depended-on their community is, but a lot of people seem to think that this line exists.