"Superhero" as a genre is as diverse as "anime", saying you don't like superhero stories is like saying you don't like anime, chances are that someone's going to grab a property that crosses over into a genre you like, and chances are you've already watched and enjoyed an adaptation without knowing its an adaptation.
Will Marvel and DC specifically fall off from the top of the heap? Probably. But TV shows like the Walking Dead, Preacher, Invincible, Y the Last Man, Sandman, and movies like The 300, Wanted, V for Vendetta show that the appeal of these stories isn't limited to capes or live action, and definitely not the traditional Batman/Superman/Spiderman/Xmen set that we were locked into in the 90s.