One piece of the puzzle I'm struggling with in all of this is why if housing is so expensive and rents so high are more houses not being built? Surely the incentive is there, what's going wrong?
NIMBYism. The incentive is definitely there but the issue is that existing landowners don’t want any more buildings. After all - more supply while keeping demand fixed hurts their profitability.
You need eminent domain from the government to fix this. At this point - it’s complete class warfare and landowners are fucking over many generations.
There are plenty of landowners that want to build. The issue is that NIMBYs have largely captured the city government and zoning restrictions have made new building mostly illegal. We jut need a government that legalizes new construction.
The amount of homes being built in areas where people want them built aren't enough to offset demand. In areas where denser housing is required (coastal cities), zoning and NIMBYism prevents it.