I also have friends who already lived together and still had one, but I think it's fine. I've had my own place for that long and still need stuff.
But I think brides do it because it's fun. I don't think the gifts matter, you aren't suppose to get anything exy anyway. It's one of those things that made the wedding impending real, we all got very excited at that point because family started arriving from interstate o/s and it starts the wedding fever.
Its all fun.