Yeah, first you had to a) know that fanfic was a thing other people did and b) find the mailing list.

I learned about fanfic from a Star Trek book and about my first fic mailing list from a friend at summer camp. These days all you have to do to know that fanfic exists is like. Also exist. And then if you want to read some, you can google 'fanfic + character name'. Google is getting worse but at least it's there now.

I won't try to argue that finding good fic is easier, but finding online fic fandom at all definitely is.