“Brave New World” is a serious, plodding exercise in continuity extension, without any real-world resonance even when placing a Black man as the human embodiment of the United States. It represents the MCU on autopilot, and while that means everything runs smoothly, it never goes anywhere particularly interesting.

For much of the history of the M.C.U., Captain America was synonymous with Steve Rogers, the frail but big-hearted young man who transformed into one of Marvel’s most recognizable heroes when he received a super serum and an indestructible shield.