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.