An interesting story in the two most important Canadian cities in my life, Toronto and Montréal, tell is about density. Toronto is in a gas-fueled affordability crisis, real estate prices have left the solar system. Montréal is starting to heat up but by most metrics is still considered affordable. While there are several externalities (language barrier au Québec, higher paying jobs in Toronto), one of the biggest reasons I've seen cited is the extreme amount of rental apartments available in Montréal. A mass exodus 1980s-2000s with the FLQ crisis, parmis d'autres, freed up tons of buildings from the 60s and 70s which still have not been saturated 'til this day.

The huge selection of functional, old apartment buildings has a price-depressing effect on local real estate. Why would I buy a house for 700k ($3000 mortgage, etc) when I can get a 5 1/2 (3 bdrm) for $1200 a month within biking distance of downtown. Now, while this helps explain the current situation, the lord knows that nobody in their right mind would consider investing in non-luxury apartment/condo towers when they have so many other lodgings suppressing home values. But that's kind of what needs to happen in TO as well, IMO.