This review may contain spoilers. I can handle the truth.
ScreeningNotes’s review published on Letterboxd :
This review may contain spoilers.
Trauma. Half the world is dead. How do you deal with that? You go back to work like Natasha, you start a support group like Steve, you use this as an opportunity to find yourself like Bruce? You have to move on and do something, because you can't change the past. Or can you?
Power. Thanos is still alive and must be punished for his evil acts. But beheading one madman doesn't rid the world of power; Thanos may have been evil, and he may have wielded power, but he was not power incarnate. The Infinity Stones are power, and you can't just rid the world of them. Or can you?
Change. Thanos forced his vision of the world upon you, but now you've claimed his power for yourself. So what do you do with it? Do you change the world to make it a better place? You can't just return it to the way it was before. Or can you?
There's a much more interesting version of this same three-part thematic structure wherein the dead are still brought back, but doing so only makes everything worse: the returned are broken and confused about the 5 year gap between their death and rebirth, the psychological healing done by the survivors in that time is undone, people who healed regress; and now the Avengers have reassembled the Infinity Gauntlet and alerted past-Thanos to it, reintroducing the ultimate evil into this even more broken world.
This isn't just a more interesting movie because it's dark and dour and because happy endings are bad or whatever; it's more interesting because it takes its own themes seriously. In the real world we can't go back in time and erase our trauma (for all the movie's cute protestations against Back to the Future-style time travel corrections, this is exactly what it does), but even if we could in this theoretically sci-fi universe, it wouldn't make things better. That's not how trauma works. But in the world of Endgame, everyone returns from the dust and everything is just as it was. Trauma erased. In the real world you can't just eliminate power, but in Endgame you can send the Infinity Stones back in time and erase them from existence.
And what do the Avengers do while they wield this immense power? Bring about a utopia founded on their own principles of justice and equality? Nope, they return to the status quo. And while at first this seems to be a limitation on their individual abilities (i.e. they're barely able to use the Gauntlet at all), this move "back to normal" is always their goal from the start, and no one even brings up the possibility of using this power for good (they do realize that "normal" isn't good for, like, most of us, right?). Tony brings this up himself when he returns from drifting through space, even if the movie undercuts him: the Avengers are, for all intents and purposes, against change.