(Warning: The following contains fairly substantial SPOILERS for several superhero movies that you've probably already seen, including Captain America: Civil War, and Batman v Superman: Dawn of Justice. Proceed with whatever level of caution that suggests to you is wise...)
Now, one of the more unusual side effects of the current cultural (and box office) dominance of superhero movies is the fact that we, as a society, seem to have decided on a whole bunch of arbitrary rules and regulations for superheroic cinema without, y'know, putting it to a vote or anything. That's why there seems to be a wide-reaching consensus that you need a certain number of jokes, and a certain level of po-faced seriousness, in order to be a 'proper' superhero movie. It's also why, for some reason...
We All Seem To Think That Death Is The Only Way For Superhero Movies To Raise The Stakes
Take the recently released Captain America: Civil War, for instance. Not only did some fans and critics take issue with the movie for not really killing any major characters, but there was a widespread media preoccupation with the less central characters that the movie did kill off. As a collective cultural conglomeration, we all seem to have assumed that major superhero movies have to kill off a major character once in a while, in order to somehow keep things realistic and grounded.
Here's the thing, though...
It Doesn't Matter How Many Characters You Kill - Superhero Movies Can't Ever Be Truly Grounded
These are, after all, movies about guys in flying robot armor fighting 1940s super-soldiers that we're talking about - or, in the most grounded Marvel movie to date, literal Ant-Men. These are films in which believing a man can fly - and be from another, somewhat explosion-y, planet - is something we've all already accepted going in to the theater. In other words? Superhero movies aren't grounded in anything like our own reality, no matter how many random criminals Batman guns down - and that's a huge part of what makes them so beloved.
We don't go to see superhero movies in order to see our lives reflected back at us in subtly drawn and grittily realistic ways. We don't sit down in front of Captain America: Civil War hoping to watch Cap struggle to pay his bills, or get chased down by the dastardly menace of the student loan people. We don't look to Batman v Superman: Dawn of Justice to offer up a documentary-like look at the world we live in now, only with more Batmen.
We Look To Superhero Movies For (Increasingly Intellectually Stimulating) Escapism
There's been a genuinely fantastic fashion in recent years to imbue major Hollywood superhero movies with genuine political subtext - and often overt debate. Which is great, and all - but it's not ultimately why we drop ten bucks on a movie ticket.
In the end, we still look to superhero movies for something a little like wish fulfillment - a two-hour glimpse into a world in which god-like heroes battle evil on our behalf, and show fleeting moments of humanity in order to allow us to identify with them. The fact that those heroes are increasingly well-drawn and realistically brought to life makes that more appealing - hence the wild popularity of the Marvel Cinematic Universe and Christopher Nolan's Dark Knight series - but they still remain, at heart, escapist fantasies.
And there's absolutely nothing wrong with that. In fact...
Superhero Movies' Escapist Nature Is Precisely Why We Don't Need To See Heroes Die For There To Be High Stakes
Y'see, the vast majority of superhero movies consciously offer up a cinematic world in which actions have consequences, but not necessarily fatal ones. Heroes can die, but more often than not they survive, or come back to life - because they're heroes, and sometimes we need them to make it through, no matter the odds.
Michael Chabon's novel - The Adventures of Kavalier and Clay - is probably the greatest (fictional) book ever written about superheroes for one very particular reason: It takes as its central theme the idea that superheroes offer us hope in the form of escapism (so much so, in fact, that the central superhero is named The Escapist). That idea - that comic-books can help us to process the harsh world around us, but also give us something to believe in - is why so many people were upset about the idea of Captain America (sort of) being a Nazi. It's not simply that he's a hero to millions, but also that he was created as a direct act of opposition to the Nazi ideology - a hopeful gesture from two young Jewish guys from New York City, unwilling to be left powerless in the face of tyranny the likes of which the world had never before seen.
In that context, superhero movies don't need to kill off a major character every few months in order to keep the stakes high, because living or dying isn't the ultimate matter that they're trying to settle. They're not war movies, defined by whether or not certain characters live or die - they're stories of idealistic heroism, and of real-world reflecting villainy. They're not tales of survival, but of iconic, intentionally implausible idealism. They stand in the face of death, and say, in the words of J. Michael Straczynski, "no, you move."
Death, then, isn't the only - or perhaps even the right - way to raise the stakes in that sort of story - being simply a defeat, albeit sometimes a noble one. Instead, superhero movies can offer up entirely different stakes. The potential loss of friends and family as the result of doing the right thing, as in Captain America: Civil War. The potential loss of what made a hero heroic in the first place, as in Batman v Superman: Dawn of Justice. Simply fighting on, no matter what, as in every Captain America, Spider-Man, Wolverine or Iron Man movie ever made.
Superheroes, in the end, don't need to die for what they do to have mattered, or for us as an audience to invest ourselves in the risk inherent to what they do - because we're not watching to see whether or not they live or die.
We're watching to see them be heroes.