Although the housing market began recovering from the 2007/2008 mortgage crisis in 2010, new single family home construction stayed low.
It might be assumed that the cost of land in Silicon Valley is the main cause. If you look away from Silicon Valley to for example Contra Costa County, you will see very low home construction. Apparently all of the various costs of building have risen beyond the ability of people to pay for it.
Betting that the cost of a house will drop, looks like a losing bet.
Take a look at the effect that higher interest rates in 2018 and 2021 had on Santa Clara County house prices:
Real estate trends for higher priced cities are similar: Palo Alto real estate, Los Altos real estate.