The thing is it's super hard to start a niche community due to a fundamental issue with federation. Which instance do you start the community in, and how do people find it?
With reddit you just needed /r/[obscurehobby]. In lemmy you need to check all the instances, and you may find a different versions of the community, but all of them are dead with like 2 posts from 8 months ago because they never got the critical mass needed to catch on because the community was split.