How do you fix the issue? Costs are costs and there is no right to subsidized living in the private market regardless of the tenants advocates say.
The mess in rental housing started with rent controls and these were compounded with changes to the income tax act which removed the immediate tax deductibility of all upfront costs of constructing new buildings.  This, of course, was all part of "social justice" as it hammered those Snidely Whiplash landlords and made them pay their "full share" of taxes.  Of course purpose-built rental development died and so began the shortage of rental market housing.