So my 14 year old has an idea that he's calling the "Million Adam Smashers" argument. The reference is from Cyperpunk 2077, where there is a character, Adam Smasher, who has turned himself into a living tank, a complete cyborg in which the only thing still human is his literal brain. My son's argument is this: as a creator--a writer, game designer, manga artist, whatever--you need to ask yourself, why is this guy unique? Why are there not a million Adam Smashers? All you need is money, connections, and a specific mindset that allows you to cope with or disregard your supposed lack of "humanity", and you too can be Adam Smasher. And he's right; there should be dozens, hundreds of rich assholes who might otherwise get into racing or yachts or something but if you can become a terrifying cyborg capable of stopping a car with one hand, at least some people, out of the billions in the universe, would choose that. Why don't Arasaka and Militech just have twenty Adam Smashers apiece?
More broadly, he's making a point about fictional characters, usually main characters--is what makes them special, you know....actually special? Are they the main character because these things happened to them, or did these things happen because they're the main character? Why are they Adam Smasher, and not someone else? It's a test; a check to make sure you're not favoring the character because you're enamored with that character.
I think it's an interesting mental exercise. Take a good look at your universe and your characters and make sure that if there's only one Adam Smasher, only one Captain America, only one Rock Lee, only one Joker, there's a good reason.