If you recall reddits growth many of their communities evolved as offshoots of a single generic community. This made it easier for people to see discussions they normally would not get involved in, and once the posts in a similar category reached critical mass it moved to a sub Reddit.
I think people are recreating their niche communities here but they are floundering since the user base is still pretty small. Maybe it’s best to post to the “big” communities until the time is right to move to smaller, targeted communities?
What beehaw has done with limiting the creation of communities has worked well, since the ones they created have been pretty active.
Not all instances need to be that strict, but might be good to have a place to propose a community, why they’d be a good mod, and type of initial content they plan to post themselves before it grows would help until the user base is bigger to be able to sustain random free for all creation of communities. Some places just exist with nothing posted at all, so you’re not sure if even the person who created abandoned it from the get go.