Builders aren't making much money due to material and labor costs in addition to land costs. It is probably impossible do a non-ADU project for just $700k, so dumping money into the problem isn't going to help make things cheaper. This is before we get to regulation and zoning, which are not even close to being the bottlenecks right now. I wonder if we could invest more in making building cheaper (via prefab?), and then more building would happen and prices would actually fall.

We (Seattle) are also completely built, new projects must overwrite existing housing stock and additional capacity only comes from increased density.