[hntrader]

Homes aren't a natural monopoly. Highways largely are.

  "there is not enough available/affordable land to build competition"

There definitely is in the large majority of places. The only city that can possibly say that honestly is Hong Kong, but even there they could go a bit more vertical and more dense if they needed.

  "It's also clearly not "easily addressed","

Whatever lobbying hurdles you need to overcome to reduce regulatory interference on increasing the housing stock, you're going to face those same hurdles (and then some) if we're talking about public housing. So it doesn't make sense to immediately go for the radical and untested solution when an easier and proven solution is waiting. If we build vertically and it doesn't work (which it will, but nevertheless) - only then does it make sense to consider something more radical and more difficult to push through.