So that’s already a huge advantage over other platforms due the basic design. And in my opinion it’s got advantages over the other extreme, too, a pure peer-to-peer design, where everyone would have to fend for themselves, without the pooled resources.

Mastodon deliberately does not support arbitrary search. If someone wants their message to be discovered, they can use a hashtag, which can be browsed. What does arbitrary search accomplish? People and brands search for their own name to self-insert into conversations they were not invited to. What you can do, however, is search messages you posted, received or favourited. That way you can find that one message on the tip of your tongue.