Seriously, #spoilers ahead..
First of all, you knew this was coming. If you didn’t, you weren’t paying attention. Even in Avengers: Age of Ultron, Thor had a vision, in The Cave, where Thanos killed all the Avengers.
Let’s just take a look at several things Dr Stephen Strange said during the film. “I’ve examined 14million plus possibilities..” “How many of those do we win?” “Only one.” Later, he says, “There really was no other way.”
If you put these together, Dr Strange saw the only possibility in which they won and let it play out, knowing there really was only one way to defeat Thanos, even if it was defeat in the long term. And by long term, I mean, the next Avengers movie, picking up where Guardians of the Galaxy 2 left off, “I name him ‘Adam.'” Yes, Adam Warlock, in the comics defeats Thanos, with the help of others, but it is Adam who wields the Infinity Gauntlet to defeat Thanos, also Squirrel Girl defeats Thanos, but that is another story. This also explains why Dr Strange never used The Time Stone in his fight against Thanos, like he did in his fight against Dormammu. He played the long game, the one where Thanos will be defeated for good.
This also explains why Dr Strange “allowed” Quill to get angry at Thanos, hitting him and waking him up 2 seconds too early, (Tony Stark in his Iron Man Nano Suit & Peter Parker Spider-man in his Iron Spider suit almost removed the Infinity Gauntlet, yes, they just needed 2 seconds more). So if they did succeed in removing The Gauntlet, would Thanos rise again at some later time, needing Squirrel Girl to defeat him? (again, another story..). I believe Marvel is saying Thanos would rise again and the only way to defeat Thanos for good is to let him destroy half the life of all the universe… and come back later to defeat Thanos for good.
Captain Marvel will play a pivotal role in defeating Thanos, and removing the Gauntlet. Adam Warlock can wield it and reset the universe to how it was before Thanos, even restoring all of Asgard and Nidavellir, (the realm of the dwarves).
Once this happens, Wanda, the Scarlet Witch, can destroy several of the Infinity Stones and have the Avengers protect the rest. I would have Wanda destroy the Power Stone & the Reality Stone, as they are too powerful to have lying around, even The Collector could not protect these Infinity Stones. Give the Time Stone back to Dr Strange for safe keeping and as a great defense against threats to Earth. Give the Mind Stone back to Vision, so he can become Vision again, unless Shuri can reconnect neurons and make Vision without the need for the Mind Stone. Let Thor use the Space Stone as the Tesseract again, because that was convenient, and as for the Soul Stone? I’m not sure. Definitely have Eitri melt down the Infinity Gauntlet so it can never be used again.
This is a response to all the angst on twitter right now.. (don’t worry, in two years, all the ones who disappeared at the end of the movie will be restored).
Also, Disney just used the word assh*le in a Marvel film, way to go MCU. It wasn’t even an emotional moment, just Banner in the.. Were they trying to top the last Avengers movie, with “language, Cap?”