The 2012-2016 American Community Survey 5-year Estimates had the median household income for New York City as $55,191. Is it a single income household? Even if so, that's median. Hardly "shitty."
If you want to own your home and drive a big car, you don't live in an Northeastern U.S. metropolitan center unless you're rich.
It's not an apples to apples comparison.
London generally has stupidly high housing prices, because it's filled with empty apartments owned by rich people from other parts of the world. It also has really expensive restaurants. A lot of other things are cheap, especially groceries, although that may change dramatically with Brexit. Like roommates? London seemed really cheap coming from Washington. Hate them? London will probably seem expensive (unless you're from New York, then it'll still seem cheap).