This isn't true at all; for one example, the main reason housing prices are high in the US is policies that exist to maximize the supply (and thus suppress the price) of low-density and particularly the extreme case of that, single-family detached, housing (which also suppresses the value of land, since the land can only be used for that purpose)

Removing those policies will decrease the cost of the minimal housing unit by increasing supply, but also increase land prices (by opening up more valuable uses) and increase the premium for single-family homes sitting on land (since they will become rarer), so making housing more affordable will simultaneously make existing houses more valuable.