I think I'm one of the few people who don't necessarily hate Clair despite the problems with her character. She undoubtedly could use a bit more characterization of her own, but I think the primary aspect the show is trying to illustrate bout this person is that she's emotionally available and very good for Carmy, yet he isn't ready for her. Even if she's not around much in season 4, I think him eventually working his way back to her (or not) could be a powerful arc for him.
