You need to distinguish between the market for houses and the market for housing (which includes rentals). Speculative real estate purchases and home buying incentives have a much larger effect on the market for houses vs the housing market. But the housing market is what drives the cost of leaving home.

With zoning and building codes we've just made it a lot more expensive to build housing. Just building codes probably increase the cost of building an apartment by 1-2% per year, and with zoning added in that could lead to 2-3% appreciation above inflation and wages which over 30 years adds up to quite a bit.