The MCU's Spider-Man 3 has an Iron Man problem and the only way to solve it is by making Uncle Ben important to Peter Parker's origin story again. The tragically murdered father-figure to Peter Parker has traditionally been a major part of Spider-Man's origin, offering him the foundation of his entire heroic belief system (even beyond his eminently quotable "with great power..." line). But the MCU chose not to retread Spider-Man's origin after two reboots, with audiences already very familiar with how Spider-Man got his powers.

At the time, it wasn't a bad idea, because it allowed for an almost fully-formed hero to arrive into the Captain America: Civil War picture before stepping back into his own solo movies. But then the MCU filled the void left by Ben with Tony Stark and did the character a disservice, not to mention completely reframing Spider-Man's own story. Rather than becoming a hero inspired by the principles and morals of his uncle and cemented by his death, Peter Parker became Stark's pet project - a surrogate son he molded into his own image who naturally then mourned his death in Avengers: Endgame.