I think the MCU does have an over-reliance on humor and jokes that they can sometimes take any and all seriousness and gravity out of the situation, but in the cases of
Avengers and
Civil War I think they worked for what the creators were going for and the overall tone of the film. But your mileage may vary.
Notice that the final fight between Cap and Iron Man in
Civil War had virtually no jokes or humor in it.
Plus Marvel heroes are very naturally quippy to begin with, even before Iron Man became the snarky character RDJ turned him into. Stuff like "Puny God" and Hawkeye quipping during a fight are pretty in-character.
And I will always think
Incredible Hulk (and the first
Thor) are the underrated gems of the MCU
.