It's reasonably true. The movie captures many key elements and storylines from the comics, but there are some differences to make it work on the big screen.
Avengers: Endgame has both similarities and differences compared to the original comic book story. Some key events and characters are portrayed faithfully, but there are also creative additions and alterations to make it a unique cinematic experience.
Endgame originated from the Marvel Comics universe. So, in a sense, it can be considered related to comic books. It brings those comic book elements to the big screen in an exciting way.
Definitely. Endgame is deeply rooted in the world of Marvel Comics. The movie builds upon the existing comic storylines and characters, bringing them to life on the big screen in an epic way.