Exactly my thinking too - which is why I built my instance. I saw this and immediately thought that the entire point is decentralization, but so many people are just creating communities willy nilly on the main instances. And there should not be main instances.
So yeah, I created my own. I thought about what I did most of the time on Reddit, and what communities are probably already in the Fediverse and decided on mine. I'm sure some people eyeroll at pop music, but on Reddit there are literally hundreds of subs around pop music and their artists. Those don't need to be added to a main instance, those could all be hosted by another instance. So I thought why not.
(Btw if you like pop music come check us out - poptalk.scrubbles.tech)