As Levi says, Shazam and Superman have had epic battles over the years in their respective comic books, so recreating that on the big screen would be just as epic.
Superman, they might also go in on Shazam v. Superman.
It’s actually Shazam! director David F. Sandberg who first suggests to Entertainment Weekly that he’d like to see Shazam fight Superman, but Zachary Levi jumps into the idea quickly supporting it wholeheartedly.
While Shazam might not have quite the name recognition as Batman, he has the history, so if fans were excited to see Batman v.