The Marvel series Loki introduces us to the idea of the sacred timeline. It is a singular view of the universe where things are allowed to happen in only one way. When someone diverges from this "one true way", they are punished. This is a lot like some of us having this idea of "true history" - a singular view of the past that corresponds with our political views and how alternative ways of recalling the past are frowned upon or even punished. There are tribal histories, minority histories, Dalit histories and mythologies that are not remembered because they are the equivalent of divergent timelines. People who speak of these pasts are punished for doing so. So the MCU is perhaps not as much of a fantasy as it might seem because of the visual effects and the muscle mass that come with it.
And much like our real world and the leaders who seek to rule it, Kang offers an alternative. The climactic scene of Loki is almost a sort of "If not Kang, then who?" choice. The choice is simple - Should we let one individual's control of the system continue or should we end it and allow free will to flourish. We saw something similar to this when Thanos was the big bad of Marvel. He also offered two choices - let chaos continue or bring "order" by killing half the people in the universe.
Order is a seductive idea. People like order. It allows things to be predictable and it offers no unpleasant surprises. Once we have gotten used to living an orderly life, any chaos seems like a threat. Don't get me wrong, I am not saying chaos is always a good thing. Chaos can be destructive. But when we remove the potential for unpleasant surprises, we also remove the potential for pleasant surprises. Surprises like a feeble young man becoming a righteous super soldier. Or an arms dealer becoming a superhero to protect innocent lives. We remove the possibility that the world might be saved from impending doom. We remove hope.
There is no dearth of people who agree with the villain though. Every once in a while, someone tells us that Thanos was right. And doubtless, in the weeks to come, there will be those who say "He Who Remains" was right. That it is necessary to take tough decisions to maintain order. That the loss of billions of lives or the suspension of free will itself is a necessary sacrifice that must be made in order to preserve order and safety.
This argument is bullshit of course. Because it doesn't take into account the fact that the many who died after Thanos's snap were not "safe" and did not get to enjoy "order". And it doesn't account for the fact that a world without free will is neither safe nor orderly. It is merely silent. It is only compliant. It is without art, without original thought, without new ideas. And everyone who is silent in this world is in danger of being oppressed by those who maintain this order. I say "in danger of" being oppressed because it is pretty evident that the people who say Thanos was right to kill half the people in the universe usually expect to be in the half that survived. The idea of massacre only seems like a good idea until you realise you are going to be one of the people who are massacred. And when you realise that, good, old-fashioned heroes start seeming like a great idea - someone to help you and protect you. Right?
The other reason people often think the villain is right is because they have succumbed to being programmed by the storyteller. It is the storyteller's job to make the villain a compelling character. And the best villains are those who almost make the hero think he is wrong to fight them. The hero, or the protagonist is your window into the story. You look at the world of the story through their eyes. So when you disagree with the hero and agree with the villain, you are not exercising some genius-level brain muscle that nobody else has access to. You are simply feeling what the writer of the story wants you to feel.
All this of course leads us to one inevitable question. If chaos is something so admirable, why do all these stories always end without a solution? Why do we always get endings where, though things are temporarily resolved, the bigger problem never goes away? Why is there always an impending sense of doom?
The simple answer is that the storyteller wants you to come back for the sequels. They need to keep you in the grip of the suspense they have created. It is a series of films after all and there are going to be more stories set in this world in the months and years to come.
The deeper answer in my opinion is that it is a way to imply something about the world we live in. And that is that the future will always bring challenges. There is no getting away from it. No matter how eagerly we look for that one answer to all questions and no matter what lengths we go to enforce oppressive systems so that chaos doesn't manifest, we will still have to face uncertainty and disorder. The way to avoid bad things from happening is not to kill half the people in the universe or to prevent people from making free choices. The way is resolve. The way is holding hands and moving ahead with the determination that no matter what happens, we will face it together. And if we fail, we will do that together as well.