Most of them are magic users themselves and are at times defeated with their own magic.
https://www.youtube.com/watch?v=b-qLC_ptImo
That's just how DC superheroes stories went.
In Marvel there are many more ... Iron Man, Thor, Hulk, and Sentry.
And they're not magic users.
Tony Stark even said that magic is just science that couldn't be explained YET. One he could figured it out, he could always beat magic.
In the future stories, after he figures almost all of magic in science term he'll even be the Sorcerer Supreme relacing Dr. Strange.
