The US has the nicest biggest pie in the world. Why would somebody move to a place with less opportunity?
The opportunity created in the US is due to the concentration of talent, high productivity, and extensive networks of people creating innovation that inflated the pie even larger.
Go ahead and move to any of those countries from the US, it's prettt easy, because everybody wants to be like the US! The only possibly better passport was a Canadian one!
Something deeply sick has infected the US when we no longer recognize the source of the wealth of our nation. Nobody could touch us. At least until we started to intentionally make ourselves poorer.