Housing in US is in fact one of the cheapest... everywhere, measured as price per square foot as percentage of income. Several times cheaper than in many countries and at least somewhat cheaper than almost every single one, rich or poor, democratic or authoritarian.
It's just that "normal" housing in the US is what's only attainable to the very rich and only because they inherited it, in most of Europe let's say: even 1% won't be able to buy an equivalent of median new US single family house, in EU - that 1% probably owns a similar or somewhat better house but simply because they bought or built it generations before.
Got a source for this?
I'm only finding sources that vehemently disagree, and say the only countries worse for this are Portugal and Canada. Everywhere in the world is better.
That's probably because what you are googling is a ratio of price of average house to average income... Which only means that American houses are much much bigger and thus more pricey, because Americans have many times more disposable income per family than just about any nation in the world.
But if you compare the price of the SAME sized house to the average income, the situation is opposite. U.S. is the 3rd best after Oman and Saudi Arabia. It's just that Americans are not satisfied with houses even twice the size of what people in many rich countries are happy with.
American houses are large and unaffordable. The usual term for a situation like that is inefficiency.
Price per square foot is not a very useful metric, because neither utility nor construction costs scale directly with the size of a house. A 3000 square foot house is not 2x as good as a 1500 square foot house, and it should not cost 2x as much to build. Roughly speaking, walls are expensive, while making the rooms larger is cheap. And bedrooms are cheap, while bathrooms are expensive.
It's just that "normal" housing in the US is what's only attainable to the very rich and only because they inherited it, in most of Europe let's say: even 1% won't be able to buy an equivalent of median new US single family house, in EU - that 1% probably owns a similar or somewhat better house but simply because they bought or built it generations before.