Earth in comics is constantly bombarded by armies of aliens and supernatural entities, and individual superpowerful beings. There should be a comic miniseries where all the superheroes on Earth share their weapons/technology/training/genetics with the rest of humanity, and all of humanity merges into a single planetary nation, in order to be able to defend itself against invasive threats. They could even form interplanetary alliances with alien races. Earth would finally be on the same level as most other alien worlds in comics. It would be kickass.
That's why the laws are there to keep people in check. Everyone would have the same amount of power, instead of a few individuals fighting for what they want or think is right. Everyone's lives wouldn't be at the hands of a single individual who fights for them, but could change their mind and rule over them. Instead, it'd be an entire government. Of course, the government can become corrupt, but the people have always had the power to overthrow it if it got too far. If it's a single superpowered being overruling them, what can they do? Which is why you give everyone the same level of power. The person who has the most power thinks it's up to them to decide the fate of those below them. Whether it's making them do what you want, or trying to protect them like children.
Evolutionary, it's more likely "advanced" beings would turn out like us (warring between ourselves) than become an entirely unified planet. (Because they couldn't have started as a large group, and when living in smaller tribes, a fear of (/aggression towards/distrust of) other groups would be beneficial for their ability to compete & survive).