you personally dont have much choice really. You are basically forced between that lvl of film actors who can match he-man look (but not acting), and couple of wrestlers (Cena?). And for that you need really great director who can work magic around that. Even if you get better actor to sign a deal he just wont be he-man from physical stand point of view. And ofcourse there is point of script, director and studio willing to spend. Not anyone will sign on this kind of project. Certainly not guy like Tom Hardy for example who could embody both of the worlds.
And I basically dont see next Cavill or Evans, guys who would be willing look to transform their bodies for this role and become this icon.
And even worse there is sadly no next Arnold. Like he did Conan back in the day.