The one thing I’ve noticed, at least on the lemmy.world instance, is that posts I make in whatever dinkum communities I’m in show up on the front page right there as bold as brass, which never happened on reddit. I think that’s where some of these comments and upvotes are coming from. After I started noticing this I looked to see what communities the other random stuff I’m seeing on the front page is coming from and in quite a few cases they’re also from tiny communities.
So that’s pretty cool. Making a post in your niche subcommunity of choice is not necessarily just shouting into the void, and some people might actually see it even if they weren’t looking for it.
Some of it absolutely is from the frontpage, but I consider that a reason communities need more posts. Posts from a niche community actually have a chance at wider visibility. People who interact with the posts are more likely to be the kind of people who would like the community I figure.