Great question — answering as the UphillTech team:
Although, Julius has answered it pretty well and it is correct, I'd like to add words from director here. As Joe Russo explains why Captain Marvel didn't put on the Infinity Gauntlet, Q: Why Iron Man has to be the one to do the final snap, couldn’t the people like Thor, Star-Lord or Captain Marvel whom all previously have handled the power of Infinity Stones done it instead? A: Thor in this movie couldn’t do it, only Hulk was strong enough to do the snap without dying. We are still not sure whether Captain Marvel can also withstand all the power of Infinity Stones at once. The reason we choose to let Iron Man do it in the end was because he was the closest one to Thanos at the time. In all...
Full answer by A J: https://movies.stackexchange.com/a/100067 (CC BY-SA 4.0).
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