Superheroes – what are they, after all?

In my argument, and as I reminded in here, there are no pure-blood superhero flicks – instead, they are a mix of genres, one of the genres being accidentally the superhero one. Chris Evans says about the same thing when actually comparing Jason Bourne to a comic book hero.
But what he adds is even more interesting: “You could take any superhero movie and if you ground it enough, if you make it real enough—that’s what I think [Captain America: The Winter Soldier directors Joe and Anthony Russo] do really well. Certain superhero movies feel like superhero movies. Russo movies almost feel like human stories with a little bit of superhero sprinkled in. So you might get exhausted of the larger-than-life powers I suppose, but as long as the filmmakers keep on reinventing the flavor and the approach and the tone, audiences are going to still go.”
So, in a way, he says that the technology can advance as far as replacing human actors completely – however, without a human element to them (that is what grounding a superhero flick means, I presume), the genre will be doomed.
What do you think? Is Evans right? What about Snyder?
