The greatest feature of the United States of America is that it was never a nation state.
Our problems aren't created by uneducated people, they're created by educated people who are taking advantage of uneducated people. Removing that step from the equation makes their job easier, not harder.
One problem wit the United States is that the technical professions have let themselves be so marginalized. The Deep Water Horizon disaster would not have happened if the engineers had as much power as the managers.
This is my point, the technical class in the United States doesn't realize it should have more political power. Scientists get kicked around too much.
Any new country should see what happened in the United States and give more power to its technical class. This would be more of a meritocracy.
This cuts both ways. See what happens in states where the border does not respect these local realities, for example where you have sunni led by shia or the other way around. Or look at Africa where Western powers drew lines on maps without respecting ethnicity.
Nation state is one form of decentralization, letting people govern themselves how they want.
Though experiment: imagine that there was a single global state, with one set of laws and institutions. How do you think that would work out?
An overreaching organization without a face for accountability is prone to disaster, as recent decades have shown. As a curiosity, the United Nations have had a former Nazi at its head. This situation was only rectified thanks to the United States.
https://unbrigandage.wordpress.com/2013/12/16/nazi-at-the-un...