Where isn't that true in the developed world currently? Very few places.
Take a look at the extreme household debt to income ratios in Denmark, Sweden, Canada, etc.
Look at the completely collapsed savings rate in Japan (stacked against their catastrophic budget / public debt situation that demands ever greater funding, while the economy has near zero spare taxing capacity). Japan has seen their real standard of living drop by at least 1/3 in 25 years and it's continuing to erode. That's the world's #3 economy and formerly an economic juggernaut.
Or look at the financial situation across most of the EU or Eurozone - most of Europe is hooked on between zero and negative real interest rates. Italy is in a ten year rolling depression. Spain, Portugal and Greece still haven't recovered. Russia's commodity based economic miracle is long over, as the price of oil isn't going back to $100 any time soon. France is averaging wage growth about 1/5th that of the US. Germany's economy has barely net expanded since 2008. Or take a look at the long-term unemployment figures for most European nations, contrasting 2006 vs 2016, it's clearly dire.
The US is in better shape than all but a few developed nations. That includes unemployment rate, income levels, wage growth, GDP growth, household income to debt ratio, cost of living, housing affordability.