That's because, in the places where housing is expensive, it's expensive because a _LOT_ of people want to live there. It's a pipe dream that you can out build demand in these places. Reducing prices of housing in nice places to live (by any means, including building) will only result in more demand up until that insatiable demand is satisfied.

Nice places to live can't support all the people that want to live there.

Because demand is, for all intents and purposes, insatiable, the dollar value of housing/property isn't based on supply and demand because supply can't practically be increased to affect demand. Instead, the price is related to what a prospective buyer can afford to pay _every month_ and, thus, is related to interest rates. Interest rates go down, prices go up to the point where a prospective buyer's mortgage payment would be the same.

People who bring up the (un)affordability of housing are never talking about Oklahoma, they're talking about the Bay Area, Southern California, New York City, Seattle, Portland, etc. All places that are so desirable, they can't practically support everyone that wants to live there.