I see the United States having a fundamental advantage: by being the only large-scale true cultural Melting Pot that invites people from all around the world (temporary pauses to that aside), it's the only place that the whole world can view as representing its future. Perhaps more importantly once you're diverse you can continue to absorbing a diverse population without massive disruption. Think about how hard it is for Africans to migrate to Europe where every time they show up they stick out and contrast that with United States where we're already a fundamentally 10% Black nation. It gives us fundamental advantages especially as Africa rises.