On Lemmy they call them communities, same for other Fediverse software like Kbin and Mastadon. I like Lemmy because it’s most “Reddit like”, but Mastadon is more mature and slicker. It resembles Twitter more.

It’s the move of the piracy sub from Reddit that pushed me over to Lemmy. I’m really glad it gave me the push to do it. Had Lemmy bookmarked for a long time, but never motivated on it.

I have interest in other communities as well. There’s a pretty healthy set on the Fediverse. Here’s a site that’s helpful in finding them on Lemmy; https://lemmyverse.net

I’m still working on adding communites and getting used to the interface so I don’t have any suggestions, but it doesn’t seem there’s a lack of active content there.