Looking at those numbers, isn’t the EU the most desired place to migrate to? Feels odd to not split the USA into its member states while splitting Europe up. How many of those potential migrants want to move to Texas vs Spain?
An American citizen can freely move to any state in the United States. A citizen of European countries may or may not be able to freely move to other European countries without citizenship related changes, visas or other sponsorship.
Anyway, for immigration that’s a bit moot as there is a universal policy for EU member states. Which was a contentious issue during Brexit.