I discuss the topic regularly on !fedigrow@lemmy.zip, I also brought it up in another topic just now (lemmy.world/post/33886241/18608911)

Reading the comments here, it seems like a lot of people would like their niche community to be active, but we have to acknowledge that with our current userbase, more general communities are already struggling to stay active, so niche ones are even harder.

Example: !movies@piefed.social is kept up active by less than 5 active posters, and that’s a generic community about movies.

!cooking@lemmy.world is probably good enough for all types of cooking, you get the idea.