Originally Posted by
Robanker
Part of the thing is that DC keeps taking stuff from Clark and giving it away piecemeal. He keeps getting scaled back, his unique quality of being the inspiration of the Legion got given to Jon, his villains are given to Kara in the TV show and the Justice League in comics. He lost his intelligence. He isn't first (this was given to other heroes Post-Crisis and it's Diana now), etc.
The one thing fans and DC generally let him keep is his strength. Of Earth's heroes, he benches the most. It's the one thing he still gets to be the best at, so a lot of his fans don't want to see it go and see the OG of the genre reduced to "the guy who is pretty good at stuff but not the best at anything" when he spent his entire career taking something from his plate and handing it off so others can be stronger for it. He already feels like Boxer from Animal Farm with how often TPTB mangle him in adaptions and have him lose to everyone.
I know Diana gets humbled a lot. I'm not here to say she isn't, but she already would absolutely wreck Superman's ass in fighting ability. For my money, she doesn't get pierced by bullets (and I ignore books where she does) so really his raw stats are kind of all Clark's got going for him. He started the genre's boom. Diana and Bruce are direct responses to him. It's not wrong to want him to still be special in-universe just like how even people who may actually have reason to be more effective than Diana (like some should with Clark) generally are expected/desired to lose to her because, well, she's Wonder Woman.
To answer the OP, modern DC thinks and has conditioned readers so they only care about street level heroes/villains, so perhaps they think it'll help boost her signal.