I thought about this after seeing Infinity War. It's clear to anyone with even a passing understanding of storytelling that Thanos is the main character of the movie. He gets all the backstory, the motivation, character development and emotional beats. The rest of the cast is there mostly just to act as the opposing force. Of course they're not entirely devoid of character growth, mostly with Thor, but the emphasis is clearly on Purple Shrek.
I think superhero movies should embrace this approach more in general. Right before Infinity War we had Black Panther, which I didn't see, but I saw a ton of praise for the villain for (apparently) being a multidimensional character with understandable motivations. The fundamental problem with superhero characters is that you can only build them up so much before they have to settle into a holding pattern: a status quo of character by which to act and be ready to fight the villains. Villains, on the other hand, are by nature more malleable. In films they can be, and nearly always are, one-off expendable things. They can get character development and motivations other than "stop bad thing" or "learn to grow as a person". They can be tragic, misdirected and morally complex. Think of Dr. Octopus in Spider-Man 2 or Mr. Freeze, or even Loki from the MCU in certain respects. They can also be the show stealer like Heath Ledger's Joker.
Since we've now seen the absolute abyss that was Justice League, as well as 3 Avengers team-up movies (4 if you count Civil War), I think it's quite apparent how limited this format is in terms of being able to keep the main characters interesting. But if you put the emphasis on the villain, you can get a complete and satisfying character arc without sacrificing any mainstay characters. I think it'd be worth exploring.
I think superhero movies should embrace this approach more in general. Right before Infinity War we had Black Panther, which I didn't see, but I saw a ton of praise for the villain for (apparently) being a multidimensional character with understandable motivations. The fundamental problem with superhero characters is that you can only build them up so much before they have to settle into a holding pattern: a status quo of character by which to act and be ready to fight the villains. Villains, on the other hand, are by nature more malleable. In films they can be, and nearly always are, one-off expendable things. They can get character development and motivations other than "stop bad thing" or "learn to grow as a person". They can be tragic, misdirected and morally complex. Think of Dr. Octopus in Spider-Man 2 or Mr. Freeze, or even Loki from the MCU in certain respects. They can also be the show stealer like Heath Ledger's Joker.
Since we've now seen the absolute abyss that was Justice League, as well as 3 Avengers team-up movies (4 if you count Civil War), I think it's quite apparent how limited this format is in terms of being able to keep the main characters interesting. But if you put the emphasis on the villain, you can get a complete and satisfying character arc without sacrificing any mainstay characters. I think it'd be worth exploring.