Things become a great deal more complicated when you consider the US is not the only country on earth, and the vast majority of countries do not have the well-being of their population at heart.
The extreme cases are well known. But let's just give the statistic: the average global wage is $24000 in PPP, according to the UN. In other words, such a global system will be on average a 75% pay cut for US workers.
By the way, that's a PPP paycut, in other words a paycut without anything getting 1 cent cheaper. Not your housing. Not your food. Not your playstation. Not your cost of living. We'll be back to deciding which day in the month we'll have a little bit of meat.
The scary thing if you've ever been there is that India actually cares more than most countries for it's people.
And the truly terrifying thing is that income is distributed along a power law. In other words, it'd be a 50% pay cut for Donald Trump and a 90% pay cut for you and me.