If Goku was raised by King Kai, then he would have been stronger faster, and far funnier than he is now. He might not be stupid due to not being dropped on his head. When he literally warned goku that he needed to stay on earth and not use ssj3. Or in the early android saga.
So, After the end of the Tournament of Power and the battle against Broly, the Kings of Everything decided to make Goku the new Omni King of Everything, unaware of the danger that was approaching for the multiverse in the future.