Say that your income is at the 0.75 quantile, nationally: you're just barely in the top quarter.
Now arrange the housing from least desirable to most and look at the 0.75 quantile of that: how affordable is the entry to the 25% most desirable places to live?
How close are those places to where you earn your 0.75 quantile living?
Contrast this to a tiny country like britain or japan with only one major city london/tokyo where everyone wants to live. Where land actually is a limiting factor.
In Cleveland & Detroit and many small towns you can get literally old mansions for less than $200k.
You can get small pieces of crap an hour out of even NYC and LA for around $300k - even in this crazy market. Plus your wages will likely be higher...
SF night be the only metro in the US where this isn't possible.