The average US salary is $50k or less, that’s who is buying the groceries.
According to recent data, the median household income in the United States is around $80,610, which means that roughly 50% of Americans earn less than this amount and 50% earn more than this amount
The problem trying to compare the US to the UK is size. The UK is the size of Minnesota
So what is barely livable income in Ma or NY or CA is vast wealth in MS, WV or NM