I don't get this whole super hero shows without the supers idea....
It's not that hard to understand. For one thing, the general public isn't as comfortable with the way-out, fanciful aspects of superhero stories as comics fans are, so adapting those stories to have mass appeal means "grounding" them, making them more like the kind of stories that audiences are used to seeing and are comfortable with. You can expose mass audiences to the ideas and characters of superhero comics, but you have to dilute it for them or you'll scare them away. They can only take so much weirdness, because they're not as acclimated to it as we are. Even the successful superhero movies are relatively grounded, more naturalistic than the comics. Nolan's Batman is in a world that's played very naturalistically, although it has such fanciful things as a microwave weapon that can instantly vaporize water without hurting people and a fusion reactor that has a built-in countdown timer even though it's supposed to be impossible to turn it into a bomb. The Marvel Cinematic Universe has had to ground things as well and ease audiences into the weirdness.
The other outstanding consideration is money. A weekly TV series can't afford the extravagant action and effects that a feature film or a comic book or an animated cartoon can depict. So it's cost-effective to focus on the more normal human characters rather than the guys with the big flashy superpowers.