My very first, second and now 3rd attempt to test out Mastodon has ended the same - didn't find any interesting content or people, no reason to stick around. From memory, it feels a bit more neutral than BlueSky, but still left-leaning and a bit negative.
What Mastodon would need for me to consider it: Following of topics and users who talk about those topics. I'd want an improved UI too - Id probably look at some of the other clients, the main joinmastodon client UI is not that great.
People will tell you to use Lemmy or kbin instead if you're topic focused. But those are totally unnecessary. Just create accounts on forums and blogs like it was before reddit.
You can indeed follow hashtags.
I've been liking phanpy as a client lately. It's "catch up" mode is pretty great.
Like any social network the key is to follow hundreds of people really.