Germany's median net wealth per adult is below that of the US ($47,000 vs $56,000 for 2017). Given the US isn't renowned for how well its middle does these days, that implies something has gone wrong in Germany.
Per the OECD figures, the US is the third most productive in terms of GDP per hour worked, at around $73 for 2017.
Excluding Norway, the best off country in terms of a combination of GDP per hour worked, least hours worked per week, and highest median net wealth is... Belgium.
They have $161,000 median wealth per adult, about 30 hours worked per week and a GDP per hour worked just a notch below the US.
Here's how the OECD ranks hours worked per week:
Mexico 41.2, South Korea 40.7, Greece 39.1, Chile 38.2, Russia 38, Latvia 36.7, Israel 36.3, Iceland 36.1, Portugal 35.9, Lithuania 35.8, Estonia 35.6, New Zealand 33.8, Czech 33.8, Slovakia 33.7, US 33.6, Hungary 33.6, Ireland 33.5, Italy 33.1, Japan 33.1, Canada 32.8, Australia 32.7, Spain 32.5, Slovenia 32.5, UK 31.9, Finland 31.6, Sweden 31, Austria 30.9, Switzerland 30.6, Belgium 29.8, France 28.2, Netherlands 27.4, Norway 27.3, Denmark 27.2, Germany 26.3