Say what you will about the tenets of Thanos’ plan to wipe out half of all life in the universe, but the guy thought things through. His plan to secure all six Infinity Stones took him most of the first ten years of the MCU’s existence, true, but he executed it the first moment he was able to, did exactly what he promised and proceeded to retire to obscurity rather than rule over the galaxy as some kind of galactic conqueror after Avengers: Infinity War. Leaving aside the whole ‘killing half of all life in the universe’ thing, you’ve got to hand it to the guy, for his perseverance.
But after all this planning, why was Thanos so certain that his Snap would work? Well, a post by Excelsior1001 on Reddit (re-sharing an image by MARVELDCLEGION, which you can see below) attempts to break down each gem’s role in it. It’s well thought out, though applying some kind of logic to what amount to magic wishing stones might not be the best use of someone’s time.
Anyhow, it’s worth considering what the current status of the Infinity Stones in the MCU is and whether they could one day return. In Avengers: Endgame, Thanos explained that he’d used the power of the stones to “reduce them to atoms.” Thing is, this doesn’t mean that they’re destroyed, merely that they’re in a dispersed form. If our heroes did want to retrieve them, they may still be around in some form in the Quantum Realm.
The full set of Infinity Stones Tony Stark used to reverse the Snap were also returned off-screen to their timelines by Steve Rogers, so there’s a slim possibility we might see some of those adventures on screen someday. And my bet is that we’ll indeed see an Infinity Stone back fairly soon.
Avengers: Endgame included the dangling plot thread of Loki teleporting away after the Battle of New York with the Space Stone and what he does with it may be wrapped up in his Disney Plus TV series. Though frankly, after ten years of stories revolving around various stones, I’m hoping they give them a rest for a bit and find some other objects of cosmic power to fight over.