Earlier quoted context omitted.
Your thesis is flawed. It is illegal to build new dense walkable neighborhoods in almost all of north america. But existing neighbourhoods of that style tend to be both highly priced to live in and also popular tourist destinations, implying high desirability. The older east coat cities built walkable neighbourhoods before they became illegal.
Housing is actually more expensive outside of San Francisco, at least suburbs close to the city. I’d say there is more demand for a house with a yard in the suburbs than a 2 bedroom apartment in the city. Especially in a post-Covid world where people are working from home, who wants to be stuck in an apartment during the next lockdown?
Not per lot SQ feet