In Marvel lore, it was the idea of Marvel’s Illuminati to banish Hulk from Earth.
Hulk’s another brilliant mind for a genius like Reed Richards (assuming he’d be in tow as well) to bounce ideas off of, not to mention he has some muscle for whenever changing the world requires some otherworldly strength.
It was a storyline somewhat mimicked in Avengers: Age of Ultron, and with Hulk now in a more zen state, he would be a good addition to the MCU iteration of the Illuminati.
Considering it still seems like we’ll never get another solo Hulk film as long as Universal is involved, I’ll never turn my nose up at an opportunity to use him as a character in an ensemble movie!