Housing in California is fixed because of zoning and construction regulations. Also, more people can't move here than can be supported...and how does putting arbitrary limits on maximum rent increase the amount of people that can live here if we're already dealing with the limitation of too many people wanting to live here? That will just increase the demand...
Otherwise, there is a natural equilibrium. Many people want to live here, housing scarcity goes up. Prices go up, less people want to live here (this is already happening). What you're left with is the price reflecting precisely the degree to which people are willing to pay to live here.