So a fun fact about me is that just this week I lectured on this very topic, and as much as all of the points here are very important, I actually had a much wider claim.
In short, superheroes are prophets.
No, like, legit. Prophets.
The rambam talks about the principles of prophecy in Guide to the Perplexed, and there are several orders of prophecy. The first order is shared by all of them, and it is, in short, the fact that a prophet must be someone who sees evil and feels the need to stop it. God is on their side, that's vital, but they don't need to talk directly to God, they don't need to have visions, all they need to do is save someone. Prophecy is not a talent, according to the rambam. It is an action.
The first of the degrees of prophecy consists in the fact that an individual receives a divine help that moves and activates him to a great, righteous, and important action - such as the deliverance of a community of virtuous people from a community of wicked people, or the deliverance of a virtuous and great man, or the inspiring of greatness.
(this is a somewhat edited paragraph, as I'm contrasting the english translation with the Hebrew translation with my dad's knowledge of the original Arabic text and finding it lacking.)
My lecture went into great detail showing parallels between different comic book characters and people from Jewish history (specifically moses and superman, david and captain america, and my personal favorite, "Other One"/Elisha Ben Abuya and magneto). But beyond that is my claim that we learn something very important from the first Hebrew - Abraham himself. Because his task is not only to create a people and teach them what is righteous and to deal justice (again, an action), but also that all people may learn from his example - see above, "inspiring of greatness". The prophet must not only serve his own people, but also the whole world.
This is why superman's motto includes not only the "american way", but also "truth" and "justice". This is why captain america becomes nomad when he is disillusioned post watergate/rebels against his own government in the winter soldier. Because there is a universalism inherent to the Jewish hero that requires that we not only help ourselves but also everyone we could possibly help (this is in the mishnah as well).
And with magneto, I claimed that what makes him a villain (an anti-villain, but a villain nonetheless) is the very fact of his interest in his own people alone. He cares for mutants and mutants alone, and even though his interests at times align with those of all of humanity/the marvel universe, if they don't he does not hesitate to turn on those he might have teamed up with previously.
I didn't say this in the lecture because I didn't have enough time to research it properly, but I don't think it's possible to imagine a world in which we have comic book heroes that in any way resemble our own in an alternate history where Jews weren't the people behind the concept of the superhero. Whereas christians value speech, self-sacrifice, and forgiveness, Jews value action and change.
It's not just that our superheroes are Jewish.
It's that they can't not be Jewish.
And this is why any time somebody turns superman into a christ figure I look at them crooked. You think that superman is in any way the type to sacrifice himself? He is the savior not because of his powers of speech or getting people to follow him. It is because he inspires greatness in others, and above all else, because he gets shit done.