The parent also mentioned Jane Jacobs who a lot of people like to remember for getting highway construction blocked and, as they say, supported walkable neighborhoods that were communities. I would also guess that Jacobs would also have been perfectly fine with Wet Village "NIMBYs" blocking high-rise residential construction if they didn't want it. Livable neighborhoods probably correlate better to high housing prices than low.

Is high-rise (>10 storeys) really needed? Or would mid-rise (5-10) be sufficient?

Certainly some areas could use high (near major transit hubs), but towers don't have to be planted everywhere.

Toronto is a good example where you can decent density without high rises.

The fact that so much land was wasted building low-density (North York, Scarberia) sub-divisions (not even getting into McCallion and her disaster of Mississuaga) now means there is high demand but limited supply. Of course now the regions of Peel and Durham (etc) have 'found religion' with regards to density.

It's also a bad example of density for a major North American city. Toronto (4,334.4/km2) has lower pop. density than San Francisco (7,255.12/km2), and Boston (5,531.93/km2) and its nearest comparison is probably Chicago (4,573.98/km2).

"Toronto" now officially includes things like North York, Etobicoke, etc, which are car-centric, post-WW2 bedroom communities.

Old Toronto is 8,210.4/km2 (21,265/sq mi):

* https://en.wikipedia.org/wiki/Old_Toronto

Even Etobicoke may not be very low-density in places like Long Branch and Mimico.