> Why would this happen? You're talking about the construction of more housing like it's free.
Not free. Less than the market price of existing real estate.
Suppose you have a 10,000 square foot building and it costs a million dollars to knock it down and build a 20,000 square foot building on the same lot. If doing this would cause the new building to be worth $500,000 more than the existing building (because local housing supply is high relative to demand), you're not going to do it, because you'd lose half a million. If doing this would cause the new building to be worth $1,500,000 more than the existing building (because local housing supply is low relative to demand), you are going to do this -- unless prohibited by zoning. Because you'd make half a million.
So when housing prices go up, you'd get more construction, until they go back down below the construction cost.
That doesn't cause housing prices to hit zero, but it establishes a long-term price ceiling, because any price above it makes new construction profitable, and increased supply lowers prices. So housing costs would converge on construction costs even if demand changes.
> Are those areas desirable? I've never been.
Those areas are beautiful, and the land is cheap and hardly anyone lives there because they're far from major cities. It's not proximity to nature that makes land expensive, it's proximity to jobs.