I bet you are basing your concept of the "usual" Westerner on your own experience, and you might be surprised at how the actual average person lives even in the "West".

But to answer your question, the article defines decent living standards as:

nutritious food, modern housing, healthcare, education, electricity, clean-cooking stoves, sanitation systems, clothing, washing machines, refrigeration, heating/cooling, computers, mobile phones, internet, transit, etc.

Nutritious food is unavailable to an alarming number of Americans, transit is a mess and almost exclusively car-centered, healthcare and education are severely stratified along economic conditions, and almost everything on that list is a commodity. The USA has sanitation systems almost everywhere, but that's just because rich poop and poor poop all smells like poop. Wherever the wealthy can isolate their own sanitation, they do.