I think they are making a good data-driven argument: If supply is the issue, why are prices so high compared to the 70s when supply per capital was lower? I think one could make the argument that this doesnt address where this new supply is distributed vs where people are distributed, but I would wager that since places like Toronto and Vancouver experience the most construction that it wouldn't change the story much.

I think if I were being very critical of the article, you could say that while it provides a simple but compelling argument as to why supply is not the cause of the housing crisis, it does not adequately show that financialization of the housing market is the cause. Personally, I believe that is one big aspect of it, but if you compare other statistics between now and the 70s, you could make arguments that things like the reduction of social housing stock being the cause of the housing crisis.