Agree with most part. But why do you think Hong Kong functions well but Shanghai is a "dysfunctional hell"? I simply don't understand. Hong Kong is a lot denser than Shanghai with most people living in tiny apartments, while in Shanghai, most condo projects are geared toward families as most are 2-3 bedrooms. Isn't it what Toronto wants, as you seem to have implied? In Shanghai, there are a very low percentage of one bedroom new condo apartments (maybe 10%) and you hardly see those 400-500sf mini suites that we constantly build in TO.
Additionally, Hong Kong's condo buildings are a lot taller than Shanghai as well. I just don't see your logic here.
Hong Kong is ridiculously dense because it has nowhere else to expand. I'm not a huge fan of Hong Kong, but the terrain they are working with presents numerous difficulties. I would prefer to not live in Hong Kong if I could help it, in any case.
Shanghai looks nightmarish to me. Endless clusters of suburban high-rises. Each of these clusters is inherently car or transit centric. The whole city is divided by a gigantic network of soul-sucking highways. Commutes are long, crowded, and there's no human-scaled anything along the way.
I believe that when density is handled correctly, it actually slows things down for the better. You can create intimate enjoyable spaces where you feel like sitting by the street and enjoying a cup of coffee, riding a bicycle, walking your kid to school, etc. I think that the ultimate freedom a city is capable of conferring its inhabitants is independence from cars or transit to do everyday chores while providing a beautiful and stimulating setting.
If the GTA doubled its density (replace post-war suburbs with pre-war-style suburbs and that would more than accomplish it), it would be realistic to bike from the edge of the city in any direction to the financial district. Our main streets would be bustling with tremendous retail and pedestrian infrastructure all along. Rapid transit would pay for itself. It would be a wonderful place to live in.
If there is demand to buy thousands upon thousands of units in the city, concentrating them all in gigantic towers with mini-apartments isolated from schools and backing onto highways is not the way to go. We are not facing the pressures of Hong Kong or Shanghai. Our problems are that 1) our suburbs are not dense enough, and 2) we need more families living downtown. This project in its present form wouldn't address either one of those urgent matters. Developing a conical skyline, on the other hand, would help slowly address both - development will eventually spill out from the core and begin transforming surrounding low-rise neighbourhoods into (hopefully) successful mid-rise communities.