Instability

MatPat interprets that the central theme for Phase 4 of the Marvel Cinematic Universe is instability, the idea that even though the heroes beat the biggest threat of the universe and can retire, there's still much work to be done, thus leading to generational conflicts, distrust in authority, and eventually the old guard having to pass the torch. He cites examples from the Phase 4 movies where this happens.

Example of:
Central Theme