It is not wrong to say that many American households earn more than $100,000 annually. But the cost of living in NYC/San Francisco is substantially higher than in Florida. At the same time you earn far less in Florida than NYC even if you hold the same job.Seems like I had a different view of things. I believed that US population (about 35%) were high income ( can afford good houses like the ones you pointed out). And I believed it was because of appreciation of land prices, Social mobility and investments into stocks (while people of most other countries put money in banks).
I underestimated US income inequality.
For example, the starting salary for a teacher in NYC is $57000 and for a two income household it would be over $100,000. However, they couldn't afford a house like that in NYC which could cost from 1 million for 2 hours commute or 5-10 millions in prime location. For comparison, the same teacher would earn $39000 in Florida and for two income household it would be $78000 but they wouldn't afford $650,000 home. In the end, both family would end up unable to afford a house like this.
Beside don't underestimate tax and health insurance that would eat up a big chunk of income.