Arguably, the ending of Avengers: Infinity War gave all of us the most polarizing of responses that we have experienced since we all watched how J. J. Abrams decided to end Lost on ABC in 2010.
And just like how none of us believed how all the characters on Lost were actually dead for the entire duration of the series, similarly, no-one actually thought that Thanos would actually be able to pull off the whole "bringing balance to the universe" thing by killing off half of the world's life, but when he did it in Infinity War, while managing to kill off many of the Avengers in the process, audiences, lost their collective sh*t.
It's still really difficult to believe. Yet, why are we as comic book fans so hung up on this with Avengers: Endgame right around the proverbial corner? Perhaps, it's because the entire set-up in Infinity War was so brilliant, that it managed to trick us into some kind of sense of security, when it came to the film's narrative; There was no way that Thanos was ever going to pull that whole thing off, but we were also tricked by how everyone thought that the movie was going to fall in line with the story-line from The Infinity Gauntlet, when, in fact, it didn't really.
At this point, Avengers: Endgame really has an "anything can happen" feeling. With Thanos, having snapped his fingers and turned on the infinity stones, some of the Avengers allegedly dead -- how in the hell can those who are left survive, yet, save the world?
It seems like the only way out of this situation, right now, would be for someone to do some sort of time travel that would allow one of the Avengers to go back and either warn the others of Thanos's plan or directly stop it before it happens. One of the easier ways that this could be done would be for Ant-Man to go back in time so that he could tell the others of what Thanos was either planning on doing or had already done.
While, this seems like the fastest and most logical way out of the predicament that the Avengers will find themselves in at the start of Endgame, and is also, one of the most readily-accessible fan theories on the internet today with a quick Google search, it also comes with a bit of baggage.
It's too easy. But is it, really? Marvel fans that have spoken up against this idea, have done so for a variety of reasons, one or two of these, being: one: it would be too predictable, and two: it would be too easy, natch, unbelievable. Wait a minute? Do believably and the Marvel universe even belong in a sentence together? Exactly, how far removed from reality itself does one need to be to question the notion of believably and the Marvel Universe? After all, these are movies and not reality. There isn't a Donald J. Trump in the Marvel Universe, yet, perhaps, that is what gives the Marvel Universe its charm.
A writer at Esquire feels that this time travel idea would be brilliant because it would also help to explain "some of the happenstance in the past Marvel movies." But also could be used to re-invent the origin story. Which has always been beset on great coincidence.
But, Marvel fans that seem like they are against the idea, in the upcoming April 26th release of Avengers: Endgame, argue, that this whole notion of explaining "convenience" within the Marvel Universe would be too easy of a way out of the whole situation with Thanos. Too predicable. Unbelievable. This is a comic book movie. Aren't these stories based on these, phantasmagorical ideas in the first place?
Isn't this the whole crux of the comic book world? Aren't the stories that Marvel sets up, in the first place, along these lines, always? Don't origin stories, for example, always begin in this fashion? Aren't the "actions in the past" what allow "some of those moments to happen," in the first place in the Marvel Universe?
As the Esquire writer suggests: "Yeah, superhero movies are pretty much based on coincidence. Almost every origin story is thanks to some sort of serendipitous moment--getting bitten by a spider, a chance meeting, etc."
So, why are fighting against the natural ebb and flow of how these stories in the Marvel Universe were devised in the first place?
Avengers: Endgame First Look Promo: