Avengers: Infinity War Theory - The Infinity Gauntlet Was Booby-Trapped
Maybe Eitri was the MVP?
Think back to the ending of Avengers: Infinity War without the emotion of having seen so many heroes (and innocents) wiped out of existence and the most important thing you should have taken from the snap was the cost it came with. Thanos himself told the projection of Gamora that it had cost him "everything" and the director's commentary bundled with the digital release of Infinity War confirmed that the Mad Titan was damaged when he used the Gauntlet.
The Gauntlet itself was also very obviously damaged in the wake of the snap, supposedly doubling-down on the suggestion that using the Infinity Stones on that sort of global scale could only be done by already supremely powerful beings. But what if the damage to Thanos wasn't about the power of the Infinity Stones and more to do with a safety net built into the Gauntlet itself?
What if Eitri, the King Of The Dwarves, built a booby trap into the Gauntlet that would actually weaken Thanos and ensure that he couldn't use it again and would thus be more easily defeated?
Think about it... Eitri is a master forger who is capable - even without his hands - of making a weapon as incredibly powerful as Stormbreaker. And that was no small trinket of a weapon: we see during the film's finale that it is capable of resisting the power of the Infinity Stones when Thanos attempts to blast Thor away during his "killer" attack. It and Thor manage to shrug off the combined blast without any obvious real effort.
So why does the Gauntlet crumple as it does when Thanos uses it? Eitri made Stormbreaker for a singular purpose - to kill Thanos - and it inherently came with such an invulnerability factor so that it could fulfil its purpose. Why is the same not true of the Gauntlet?
For it to be damaged by the one job that it's supposed to have, there has to have been a flaw to it. And for their to be a flaw, Eitri has to have built it into the artefact himself. Otherwise, his reputation as a great forger of some of the universe's most powerful weapons would be entirely misplaced.
So what if Eitri built the damage in as a failsafe? He could have reasonably guessed that Thanos' plan was to use all of the Stones together (he'd have to tell him that for the Gauntlet specs at the very least), and that he would need to be taken down by whoever stepped forward to save the universe from him. The idea of him designing a flaw that would fundamentally damage Thanos and his primary weapon in that context makes a hell of a lot of sense.
Avengers 4 needs to change Thanos' condition in order for him to be defeated, even with the unknown quantity of Captain Marvel incoming. We can't expect to see a smaller group of heroes managing to take down a fully-powered Titan with the Gauntlet still operating as it did and the whole point of Infinity War is that sacrifices have to be made in order for the greater goal to be realised. If that's not the main storyline of Avengers 4, it will be a shock.
Essentially, Eitri made sure Thanos' sacrifice to use the Stones was amplified and actually weakened him to perhaps give the heroes a chance to eventually take him down.