Not even email. Usenet is almost identical to Lemmy. There are many Usenet servers which talk to each other and synchronize their message groups. And you connect to one of them with a local account.
IRC as well but more chat like.
Of course there are differences in the fediverse but the big concepts are hardly new. People are trying to overcomplicate it.
I only saw the original video of this format for the time last week and it's just so good. I can now hear their voices in the meme.
https://youtube.com/shorts/LESg07OBuck