Exactly. And that would be a a tedious task. There are big and known relays and smaller ones. But everybody can add a relay to the network. You could rent your own relay for a few Dollars a month, even if you don't know how it works.

And depending on the the client, people can mute you, which then is only a personal decision, that has no effect on the overall reach of the muted person.

Because on Twitter it's different. If a lot of people block you, the algorithm automatically decreases your reach.