It's hard to say for sure. Different people might have different ideas of how the story ideally should have ended depending on their expectations and interpretations.
It depends on the genre and the themes of the story. Different types of stories might have very different ideal endings based on what the readers or viewers expect and what the story has built up to.
They face challenges mainly through teamwork. Despite their differences and past issues, they come together for the time - heist. They use their individual skills, like Iron Man's intelligence in devising the time travel technology and Captain America's leadership to keep everyone on track.
Overall, Avengers: Endgame takes inspiration from the comics but creates its own unique storyline. There are characters and events that are exclusive to the movie and not found in the comics. The movie also alters the power levels and motivations of some characters to fit the cinematic narrative.
The ending of Avengers: Endgame in the comics is quite complex. Many heroes make heroic sacrifices, and the universe undergoes significant changes to restore balance.