system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are mostly dramatic/serious/"adult" movies always nominated for ever "best picture" award, rather than any normal blockbuster movie like Avengers, Dark Knight, Harry Potter, etc.?
gpt
The Best Picture award is for the "Best" movie, encompassing most aspects regarding film: directing, acting by the lead cast, acting by the supporting cast, writing, cinematography, score, set design, etc.  
  
This is why Best Picture nominees usually are up for many other awards as well.  
  
Just because Avengers and Dark Knight type movies are really cool action movies, that doesn't make it Oscar worthy. While Robert Downey Jr. IS Tony Stark, his performance as Stark isn't as good as Keaton, Cumberbatch, Redmayne, etc.