There is something very important missing - the SPM poverty measure is relative poverty, not absolute. All this means is that CA has many rich people.
We had one in town when I was a student. The thing had a name. It was called Schweinebunker.
For 1900 $/mo, you can get a bedroom in a really nice 2 or 3BR place in the desirable neighborhoods or a studio/1BR in the undesirable neighborhoods (sunset/richmond). I don't understand why the people in that article are living like that (Poor credit? Desperation to find a place fast? Ignorance of the existence of Craigslist?), but they're very, very far from being representative of SF real estate.
A purchasing power metric (that includes cost of housing) would indicate that.
a) Includes income transfers, like SNAP, housing assistance, EITC, etc.
b) Is based on the affordability of a bundle of food, clothing, shelter, and utilities consumed at the 33rd percentile.
In other words, after including most government anti-poverty transfers, is the person able to afford food, clothing, shelter and utilities equivalent to that consumed by the 33rd income percentile.
It is relative, but it's not strictly relative, because it's based on a small basket of necessities.