Over half of German GDP stems from exports, which is a huge fraction and which is only possible because of the Eurozone and because of the Bretton Woods system. The Bretton Woods system was created by the US to help fight the Cold War by encouraging free trade and the US particularly since the election of Trump is not interested in supporting the system anymore. The Eurozone and the European Central Bank's monetary policy have been preventing the economies of the countries on the periphery of Europe from developing, and those countries will either withdraw from the Eurozone or at least force changes to monetary policy that will be detrimental to Germany's exports.
So it looks like Germany's exports will fall, maybe drastically. Taxes on the profit that German companies make on these exports is how Germany pays for its social programs.
When the economy gets bad in Germany, young Germans cannot find jobs. (France is the same way.) This youth unemployment has gotten so bad once or twice during the postwar period that people start worrying about riots and other kinds of social upheaval, which makes things bad for everyone, not just people needing to find a job. Youth unemployment never gets that bad in the US.
I don't see any challenges to the US similar to those 2 challenges facing Germany.
Although I concede that I probably would have been better off if I had moved to Germany 30 years ago in my 20s, let's see if you still think Germany is markedly better than the US in 15 years.
Post war Germany has never had significant youth unemployment, and worries about "riots and social upheaval" because of that unemployment? That's a pretty outrageous claim.
You cant move around in Europe if you are an average folk like you can in the US. Moving around in Europe means almost a life time commitment to the language and the country and that does not always pay off.
I think you can achieve a working level of any (European) language in around one year. And today we have Google translation in our phones, the job is 10x easier.
Nowhere is a "lifetime" commitment, but if you like a place, might just stay there.
I dont think you have even a clue about how hard european languages are and how hard it is to integrate.
So yeah, I have done that.
Its really not that hard if your study correctly and you're able to spend significant time in a country that speaks the language.