You clearly did not look at any of my sources.
>I think my suggestion that finance is the most significant factor here is a stronger argument than a supply shortage.
You have zero evidence for this claim and cited zero sources.
>The number of homes per 1000 people changed very little between 2011 and 2022. At the same time prices went from NZD350k to NZD900k.
You cannot look at an entire country's housing/population ratio and think that explains everything. New homes in Queenstown don't reduce housing costs for people in Auckland or Christchurch. You need to look at the supply of housing in an area where it is a substitutable good: where you can switch housing without switching your job, school, friends, and life.
A new house 6 hours from me does not lower the price of housing in my neighborhood.