>>121896408>>121896458People don't seem to recognize the Warners anywhere they go, while Bugs Bunny is an in-universe celebrity, so fame isn't what is keeping them alive. It doesn't matter though, in the Newsreel of the Stars segment we see Hello Nurse was still just as pretty and young back when the Warners were created, so unless she's the grandmother of the current HN then she hasn't aged either. Same goes for Ralph, who caught and threw them in the tower to begin with.
Although by the revival the Warners have grown much more famous in-universe, to the point Russia bothers to make a bootleg series about them.