Aventador117’s review published on Letterboxd:
I think one of the reasons a lot of people kind of turn their nose up at blockbusters, and why some of the more recent ones haven't been doing so hot (before COVID), is because of how loud they are. And this doesn't just include the bad ones, either. Dunkirk, imo, is a great film. But if you're sensitive to sound, I absolutely would not recommend seeing it in a theater. These films aren't just louder than they need to be; some of the worst offenders of this trend can be downright painful. I wouldn't be surprised if movies like Man of Steel or Dunkirk suffered monetarily because of how ear-splitting they were. People would see the movie, have a bad experience, and tell people about it. Thus losing the studio money not only from bad word-of-mouth, but a lack of repeat sales as well. And the problem isn't necessarily how loud they are; I'd guess the loudest part of Dunkirk isn't much louder than the loudest part of Raiders of the Lost Ark. The problem is how long they are loud. For some movies, they're going at a 9 or 10 for basically the entire runtime. That is not what your movie should do; even if it's filled with explosions.
Which is where this film comes in. For better or worse (mostly better) this is one of the quietest blockbusters I've ever seen. Even films like 2001, which spend a lot of time in the seemingly silent vacuum of space, feel louder than this. In Endgame, its music is infrequent, the action is kept to a minimum, and some of its most important moments (even at the end) are no louder than a conversation. A lot of this film is either characters talking, or doing stuff that isn't auditorily aggrandizing. Which, in my opinion, is absolutely fantastic. Not only can it let its louder moments hit harder, but even its extended setpieces remain bearable. Plus, it frequently plays against your expectations with the sound mixing. This has, without question, the quietest villain defeat I've seen in a film. The closest example I could find on this scale was Voldemort, but even that had a more rousing score and a louder death. And if you compared to something like Star Wars or Lord of the Rings, the difference is night and day. It may not be a better death in your eyes, sure. It doesn't really allow much pomp or circumstance like, say, the fall of Barad-Dur. But you can't deny that it's different. Which is good enough for me.
That's my theory as to why Endgame made so much money; its sound mixing was deliberately pared-back, allowing its viewers to be able to see it multiple times in a row without any sort of headache or anxiety. To the point where people who don't normally see blockbusters can actually enjoy it, and recommend it to others. Being the end of a 22-film saga and a direct follow-up to one of the top two cliffhangers in cinematic history is a nice little cherry on top, too.