Facebook used to just be your class schedule, and you could see the names and school emails of others in your class.
No profile pictures, no likes, not even friends.
It was just a way to email someone from class you thought was cute over the pretext of meeting up to exchange notes. That was all anyone used it for, for like the first year.
But Myspace and others already existed at that point, and it was always open to anyone. Only Facebook restricted it to people with .edu emails.