Their policies are so welcoming there isn’t a need, worker visas are easy to obtain because they have lower birth rates and a huge need for labor. There are roughly 1 million undocumented people in Germany out of a population of 90 million people, so roughly a quarter of our population. That would infer an undocumented population of 4 million for the US if all things were equal, when it fact we have roughly 40 million people who are undocumented, ten times the rate.