I don’t see the latter following from the former. First of all not all mythology has to be superheroes just because some is, and second of all that does not mean all fantasy has to be either. Game of Thrones is fantasy, I doubt anyone would consider it superheroic.
Some?
If we are taking the stance that Jesus is basically a superhero, then we are open to either Gods or Demi-Gods from other mythologies.
Greek/Roman Myth? Yep, lot of super heroics there. The battle against Typhon is a great example, or the Labors of Heracles (Hercules being an actual DC superhero, and Wonder Woman being deeply tied to Greek Myth)
Norse Myth? Loki's shapeshifting battles or Thor's Journeys (not to mention the Asgardians being actual Marvel Superheroes)
Egyptian Myth? Shapeshifting battles, fighting giant monsters that consume planets, secret magics (Not to mention Ra and the Ennead being Sentinel Comic Superheroes)
Various Celtic Myths? The Battle against the Balor, The adventures of Cu'Culain, lot of fey magic from the High Kings.
Hindu Myth is full of Cosmic conflicts.
South Pacific Island Mythology has various nature spirits duking it out, plus the adventures of Maui
Chinese Myth? The Monkey King and the the various Sages.
Japanese Myth? Plenty of mythological heroes with strange magics and great feats battling Yokai and Oni.
Sure, some of these myths feature sliding powerscales, but so do Superhero stories. For every Superman or Martian Manhunter, you have The Huntress or The Question.
But, I will grant you, not all Fantasy follows in this line. The Game of Thrones has the a very "these forces are beyond you" feel with the dragons and the ice zombies. But that just makes it a question of, as I said originally, low fantasy vs high fantasy. Just like the Myth of Galatea mostly features "ordinary" people, but Greek Myths also involve the God of Sea throwing an island at a massive monster. The larger point being, these high fantasy, high power ideas are still a very clear part of Fantasy. There isn't some great wall separating Mythology from Fantasy from Superheroes, it is more like the grass changing color from emerald green to tan.
Even if you leave all that aside, the Wizard pose, just like the Jesus pose is a power pose, it is meant to impress / awe, it has no further purpose. It is not meant to be an accurate depiction of the living person.
To the "it is meant to impress and/or awe"... yes, that was my point. Which is why I find the accusations of it being too "superhero" to be a bit off-the-mark. Not because superheroes don't make that pose, but because the problem has nothing to do with superheroes and everything to do with people not liking the power pose meant to impress and awe on a high level wizard. That was my entire original point.
As for it not being an accurate depiction of a living person.... I mean other than the floating, why not? I can stand with my head back and my arms out from my sides. If your point is that living people don't have the ability to fly and surround themselves with magical auras.... yes? Obviously? But that seems to be a rather odd angle to take, because no Tiefling or Orc would be an accurate depiction of a living person either. If your goal is to say that aspirational, high level characters should look like Ren Fair cosplayers.... why?