I don't get how the example at the start works.
In the scenario where housing prices increase dramatically, buying costs $1.1 today. In the scenario where housing only keeps pace with inflation, buying costs $1.75M and renting costs $1.3M.
Why is renting in a world where we build a lot more housing somehow more expensive than buying in a world where we don't?
I think this writeup also doesn't meaningfully touch on the _end_ of the scenario, when it's assumed that Alice sells the home, and is again faced with the choice of where to live next, and whether to buy or rent. In the case where housing prices have increased substantially, she's realized a considerable gain, but all the other houses are also substantially more expensive, and that gain is all directed at paying for her own future cost of housing. I.e. even if you're a homeowner and you've gotten your home value to increase, you don't really get to realize that gain if you still need to live somewhere.
For that reason, I think the downside to building a lot more is less dramatic than this writeup suggests. If your particular home value drops because you're in an uninsurable flood zone, that's a problem. If _all_ home values drop, then your house can still be sold and used to buy another similar house. Yes, when you die your family will inherit a less valuable house -- but they will also be richer in the sense of having smaller housing costs.