Re: $54K median ... LOL
Yes, in many parts of the US purchasing even a small house on a $54K annual income would be financial suicide. And in many places AirBnB has encouraged landlords to convert long-term rentals into short-term ones, driving long-term rental prices up.
Medical costs in the US are also high and fall mostly on individuals. My wife and I have what's considered "good" dental insurance, for example, which covered $600 of a $1400 procedure for my wife recently. And you don't want to be in a traumatic accident in these parts; if the local hospital doesn't have room or feels you need some type of care they can't provide, they'll ship you off to the nearest alternative – and since there's no longer a ground ambulance service which will take you, that means a helicopter ride that will cost you, personally, tens of thousands of dollars.
Fuel prices here are relatively low, but lack of public transit means many people do a lot of driving.
Education in the US is, of course, wildly expensive in the general case.
Median salary really isn't a useful point of comparison, or benchmark for what's required to achieve a "middle-class lifestyle", however that might be defined.