If you come to SF intending to rent an apartment on a 2x factor, you will be homeless.
The insane rents in SF is an express of the extremely constricted supply - which has other effects beyond merely just rent. It's a landlord's market and they can afford to be extremely choosy about who they rent to.
Since I'm doing contract work and don't have a regular salary, one landlord told me outright that even though I had demonstrated I could pay, he wouldn't rent to me because he "wanted a more stable tenant".
It feels terribly insulting to be told that, and makes me long for a humbler city like Chicago or Minneapolis, where if you have money, a landlord will take it without nearly this level of nonsense.
Or Berlin. I looked at apartment prices there and began to feel quite jealous of the Germans :)