You have a false assumption at the start. Germany has a much lower per capita disposable income and per capita GDP and consequently, a lower standard of living than the US. Both per capita GDP and per capita disposable income are 10 to 15 percent lower in Germany the US.
If you premise that German tools are superior to US tools, perhaps it is rooted in different cultural experiences. The US has a history of being a disposable society. We are quick to move on to new ideas and that has served the nation well. We embraced new manufacturing techniques, we lead the world in innovation and maybe that plays to the idea we don't need hand tools that last for generations. Maybe the American way is get something that gets the job done at the most effective cost. I would assume that is why Harbor Freight, Dollar stores and other purveyors of cheap, disposable products are expanding.