It's federated, mate. You don't need to be on the same server as your friends to talk to them.
Well, you used to be able to. They eventually closed it off, of course.
That's like saying you don't need search engines to view websites — your friends could just email you links to good ones. Technically true, sure.
Like, what you are saying is so nonsensical as to be not even wrong.
I /think/ you are trying to say something about discoverability, but like, it's not really that hard. You can just watch the local or federated tabs, and if you see anything interesting check it out. If someone seems alright you might even reply to something they post. Pretty soon you are having conversations, and the people you follow are boosting other nice, interesting people onto your home tab. Next thing you know, you are part of a community. It's great!
And all of this happens without the need for some weird corporate overlord to try and mediate the experience by way of manipulating you in order to keep you online longer so they can steal your data and shove ads down your optic nerves.
And where would the database live?
On the flip side, Micro.blog has a very different culture than Mastodon seems to[1], makes some very opinionated choices that many people might not agree with (e.g., there's not only nothing like retweets, but likes and even followers aren't public information), and of course, the easiest way to use it costs money.
[1]: Yes, I know there are lots of instances with different cultures, but there really is a kind of left-wing anarchist vibe across a lot of Mastodon; it's hard to explain if you haven't experienced it. Micro.blog comes across as generally more gentle, very conversational, and more Gen-X than millennial, if that makes any sense. (If it doesn't, sorry. Again, hard to explain if you haven't experienced it.)