Prices will rise anywhere demand is concentrated. There is simply not enough land in most of the Bay Area for reasonable rents, as additional supply will be quickly soaked up (just as building additional road capacity is futile, and is quickly swamped with more traffic).

You can use either the carrot or the stick to promote tech companies to either deploy satellite offices across the country or enable remote work, but this is not a planning problem, its a tech sector externality.

With apologies to Sam Kinison, "Move where the land is cheap."