Captain America and Thanos on different sides. https://www.vox.com/summer-movies/2018/5/17/17343442/avengers-infinity-war-captain-america-thanos-sequel-moral-dilemma
That’s why the most common resolution to the dilemma is some last-minute narrative twist that allows the hero to save both the individual and the many, some clever (or often not-so-clever) way of avoiding the dilemma altogether.
What’s remarkable about Infinity War is that there’s no last-minute twist, only failure. Steve Rogers and his friends make the typical heroic Kantian decision not to trade lives … and it is a disaster. An unfathomable number of lives are lost. The movie ends with Captain America sitting on the ground, devastated, saying simply, “Oh, god.”
Movies rarely do that. Blockbuster superhero movies never do that. By cutting one giant story abruptly in two, ending after the conventional third-act crisis, the low point, Infinity War is able to do something genuinely novel in the superhero genre. And not with special effects — emotionally novel.
Still. Infinity War shows the Kantian approach failing spectacularly, but as many people have noted, it fails so spectacularly that it can’t be real. It’s got to be undone, if for no other reason than the people demand more T’Challa
The other way to give that narrative twist some heft is self-sacrifice, which satisfies our Kantian instincts without running afoul of utilitarian consequences. Superheroes may not sacrifice another, even to save many, but they may sacrifice themselves, and all agree it is good. (Here’s a listicle of great acts of self-sacrifice in comic book movies. RIP, Groot.)