The Captain America movies have managed to ground the MCU by exploring the political and social climate created by the Avengers' existence. Actions have consequences and consequences influence more action.
Civil War isn't as focused as The Winter Soldier. It's also overstuffed with characters and fan service. However, the movie works by always being intriguing. Both sides of the conflict are portrayed as equally valid. The exploration of superhero accountability isn't anything new (explored in Watchmen and The Dark Knight), but it's nice to see it incorporated into a grand cinematic universe. Also, Captain Zemo is a better than average villain because while underdeveloped, his motive is interesting and not just "destroy the world."
Also, SPIDER-MAN IS FINALLY IN THE MCU!!!! ๐๐๐