As long as the European psyche is at "40 days PTO, 4 day work weeks, and generous worker protections" the US doesn't have to worry about Europe getting out from under it.

Europe is in the intractable situation of needing to double defense spending, slash taxes, gain energy independence and bankroll it with an aging population skilled in mostly legacy industries. And doing all this with a working population that has only ever known generous work/life conditions.