I don't think that's a realistic solution anymore. This is not the Golden Age when Superman was the only superhero or where all others were weaker and he was the Superman. Even Green Lantern back then was not a space spanning character.
Look at what happened immediately Post-Crisis. Perhaps the biggest complaint was that Superman got nerfed and was in no way the most powerful hero. Wonder Woman and the Flash also got nerfed while the Green Lanterns, while maybe reduced in power a bit were still doing the cosmic stuff.
I'm fine with vastly reducing Superman's power level as long as they proportionately do that to everybody. But then the GLs would have to be something like solar system travelers with the Guardians of the Solar System and so on. Batman would have to be a person of real human abilities, a really good detective and fighter who can't do superhuman stuff and just say it's not superhuman.
I am one hundred percent on board with that as long as it's not just a screw Superman thing as if he is the only one who is ridiculously powerful when he is far, far from the only one and few people seem to have any problem with other characters being ridiculous in what they can do.