Bp didn't killed anyone Eric killed himself because he didn't want to be locked up.Didn't improve himself? He won. Straight up and killed him. Than after the fight was over he offered Killmonger mercy again. MCU T'Challa actually shows leadership, compassion, mercy and nobility (not nobility through birth but actions). T'challa is able to compromise with M'Baku and they end up working together. That is true leadership. He takes counsel and isn't foolish to do everything himself but empowers those around him. He even confronts Zuri and his ancestors about their actions and takes steps to right their wrongs. He even comes full circle on Wakanda being isolationist after listening to Nakia and giving it some thought. We see T'Challa not only learn from his friends and allies but his enemies. He disagrees with Killmongers actions and end goal, but he recognizes the truth in what Nakia and Killmonger were saying about Wakanda and the plight of the world at large. A wise man learns from his mistakes but an intelligent man learns from others and T'Challa is shown to be an intelligent man in this film.
With limited allies and resources T'challa is able to rally and stop Killmongers plans and retake the throne. I also think it built off of the Civil War ending. T'Challa is not someone consumed by vengeance or self interest but someone who can and will champion the greater good.
I believe many people confuse heroism with bad@$$ery and those are two separate things.
Wonder Woman didn't have to face off against any true adversity in her film. She disobeyed her mother than left home and witnessed the death of two people she loved. Outside of that she was just far stronger than any adversary she faced. If Goliath stomped out David I'm not going to go patting him on the back for winning a one-sided fight.
I think the first two acts of Wonder Woman were very good, but the 3rd act was a little disappointing and didn't really give Wonder Woman that ending I thought the film was building towards. Diana needed a heroic send off which would have made her film a little stronger, especially considering she is the one bright spot of the DCEU.