End result would've been different.
Two different stories mashed in to one. One is Thanos trying to get Death's affection by any means necessary. He's a nihilist so that makes infatuation all the more deep. His pursuit of the infinity gems isn't a go at god level power for the sake of power but to prove his love of Death. Son been a mass murderer. Death kept shunning him. This all written expertly by Starlin cuz he had his story in mind from the jump, knew how to use Marvel heroes as plot pieces and played Thanos well off of the only other few characters that mattered; Adam Warlock (polar opposite), Memphisto (literal devil on shoulder and opportunistic schemer), Pip (for humor), and Silver Surfer (stoic hero). Everybody else just gets moved around like chess pieces and the one moment with Nebula calling back to an earlier set up.
For a movie the heroes wouldn't have much of a presence imo. The other story is their small scenes. They do what heroes do and fail. Meanwhile this mad man is desperate for attention that now he's taking on cosmic entities and when he realized his supreme power puts him over Death and he could just command her to love him the whole thing is pointless and then the backdoor trap of Thanos' arrogance being what defeats him in the end wraps the story up. And in the end Thanos ends up with another gem again as a part of larger Starlin trilogy.
That would be a mad alienating movie for MCU fans. Some alleged huge fans in here aren't even really that hardcore of comic fans to actually want that to be the movie.
