And it can't just be any old genre. It has to support serial storytelling with an ensemble party of protagonists, it has to have character attributes that can be gamified into stats and a method of character advancement and power progression, and unless you're branching off into an entirely narrative focused game it has to present challenges that can primarily be overcome through combat.
All that is why things like superheroes and spies and westerns have all struggled in TTRPG form. They're weak in one or another of those pillars, and you need all the legs there for the chair to stand.