One detail from Endgame that doesn't get talked about enough:
The Ancient One explicitly warns Banner that a universe without the Infinity Stones is left defenseless against the forces of darkness—which is why the Avengers had to return them to their original timelines.
But here’s the catch… Thanos literally destroyed the stones in Earth-616 in IW
So if removing a stone leaves a universe completely vulnerable to extradimensional threats, shouldn't Earth-616 be utterly doomed right now?