I think for most MCU films, the big action finale isn't the most memorable part - some other part is. That's not to say the finale is bad, but it may not be the highlight.
Obviously subjective but:
Civil War finale is great, but everyone remembers the airport fight
Doctor Strange reverse time battle is great, but most people remember the Dormammu part instead
Guardians 1, the final action piece is pretty good, but most people remember the dance-off
Winter Soldier finale is great but the highway sequence is even better
Maybe Iron Man 3 is the most memorable part, with all the suits? Avengers 1, since the final act is all fighting? I guess it's an interesting thought experiment. But I don't think it's really a criticism of all their finales because I can think of very few that aren't at least pretty good.
Obviously subjective but:
Civil War finale is great, but everyone remembers the airport fight
Doctor Strange reverse time battle is great, but most people remember the Dormammu part instead
Guardians 1, the final action piece is pretty good, but most people remember the dance-off
Winter Soldier finale is great but the highway sequence is even better
Maybe Iron Man 3 is the most memorable part, with all the suits? Avengers 1, since the final act is all fighting? I guess it's an interesting thought experiment. But I don't think it's really a criticism of all their finales because I can think of very few that aren't at least pretty good.