The U.S is still the world hegemon. It means they can basically print away as much money as they want and sell their debt to other countries that use USD becaus

The U.S is still the world hegemon. It means they can basically print away as much money as they want and sell their debt to other countries that use USD because the USD is the reserve currency of the world. So the U.S can keep piling on debt and show magnificent gdp growth yet not have it's currency devalued. Europe doesn't operate like that both out of cultural reasons and because it isn't a hegemon (The Euro is less important than the Dollar). If (once?) the U.S loses it's special reserve currency status, you will see a massive USD devaluation and salaries would look a lot more similar to Europe. The U.S current success is much more due to historical reasons than any policy/taxation reason.