also for what its worth they at one point werent the only spaces available (and technically still arent not just because of fraf but mspfa also has their own stuff), but there were other forums like msparp's forum, if we want to count pesterchum (which last i checked was revived to work on current hardware?) with how you could randomly chat with someone, or join/make group chats.
all my examples are rp focused because thats a lot of where my attention went but the point is those werent the Only Spaces that existed nor do they have to be (and they arent!) they are just very big and active.