>This has been a half formed thought bouncing around in my head, but I think part of the reason for the resurgence of comic books and superheroes is the simple fact that we live in a complex world where there are very few instances of Good and Evil. We live in a subtle, complex, and nuanced world, where if you take the time to dig in to an issue, you find more complexity...and a lot of really morally compromised people. We don't live in a Good/Evil world, but we want to. I think that comics are a retreat from that, a mental/moral bulwark that gives us an outlet for our need for Right and Wrong. We might not be able to figure out <insert political issue> without coming to blows, but we sure as hell can agree that Thanos is a piece of shit, and that Batman is wicked cool.
Now, I always think this, but I think we also need some amount of moralizing mythology to remind us that, at the end of the day, when the time comes to act, there really are such things as good and evil. My favorite superhero movies tend to be the ones that show it, rather than trying to add "complexity" by actually removing the mythic content by invoking gray-vs-black morality and calling it "complexity".
Captain America: the First Avenger did it well, though I'd have liked them to have kept the Red Skull as a loyal Nazi. Let Hydra genuinely be portrayed as a Nazi cult, carried from its origins in WW2 to the modern day. It's mythically important that a Nazi piece of shit gets punched in the face by Just a Kid from Brooklyn.
It's mythically utterly unimportant that one manic-psychopath and another brooding, resentful psychopath "can do this forever" (The Dark Knight).
It's moral complexity when a fortunate kid from Queens tries to find some responsible way to deal with a working-class villain just trying to make it good in a world dominated by the Tony Starks and Thors (Spiderman Homecoming). White versus mid-light gray (with a good reason to be gray) offers us a compelling conflict, in a way that "two pieces of shit fight each-other" does not.
(Yeah, Marvel > DC, and holy war upon anyone who says otherwise.)