I know about Lemmy, but I was referring to the kind of trollish, irreverent and fun community that reddit used to be (when its name was spelled lowercase), not really about communities vs microblogging.

That said, Nostr does have communities, and so does Plebbit. Lemmy is ActivityPub-based, so decentralized but not censorship resistant and the overall culture is possibly worse than that of Mastodon.

It was really about the kind of interactions typical of old reddit, not the specific functionality of communities.