This is something everyone from a fandom can relate to.

Honesty Castiel's arc still feels so incomplete to me. Yes he got to confess to Dean and tell him how good and loved he is, which is huge for him. I don't want to downplay the significance of that and how much it meant to Cas. But what about the fact that he died doing the same thing he's always done by sacrificing himself? What about how he never learned to open up about his problems and to let his family help him because he still didn't want to burden them, which is why no one ever knew about his deal with The Empty? What about how he never really understood and accepted how much he was loved and wanted? I mean admittedly I'm still only in season 13, so I'm sure there's so many details and nuances I'm missing here, but idk. Even outside of reuniting with dean his character growth just doesn't feel done. I mean Dean dying the way he always thought he would, young on a hunt with no chance of a happy ending, is horrible and unsatisfying and I hate it. I don't see why Cas dying how HE always thought he would, happily self sacrificed at the altar of Dean Winchester with no chance of a happy ending, is much better.