I think trying to determine or prove the "correct" amount of humor to employ in a blockbuster is a fool's errand. Spoiler alert: the limit does not exist. Humor either works for people or it doesn't. There's no formula for achieving the former, and even what generally works won't work for everyone. That's why comedy is so notorious for being the most difficult thing to write. For example, that Drax moment OOB just complained about in Infinity War: Every audience I saw that movie with absolutely ate that moment up. So it may not have worked for OOB, but it seemed to work for a lot of other people. People like all sorts of different styles of humor. One style includes cracking jokes after emotional moments to relieve tension. Some people like that, others don't. Oh well, neither group is likely to change, because no one can consciously control what tickles their funny bone.