Yes, per-adult, multi-generation family homes are even more cost-effective than for couples (even accounting for smaller pensions compared to salaries), and both are more cost-effective compared to singles.
Apart from growing prices, my experience (not in Canada though) is that living spaces are growing too, as we are not satisfied to live in the same cramped 20m2 studio as singles were 30 or 50 years ago.
I conjecture that this is, at least partially, caused by modern people being more isolated and even when they do socialize there's less "third spaces" to get together with friends so someone ends up having to host the superbowl watch party in their apartment, for example.
Median home sizes have gone from 1400 sqft in the 70s to 2400 sqft in recent years.
https://www.bankrate.com/real-estate/average-home-size/
Part of it is the economics of construction. Part of it is growing threshold for “bare minimum”. In unit laundry was optional in the 70s and I’ve heard people wanting a “laundry room”. Pandemic has pushed the need for an office. Larger kitchens and more storage space is also a big difference in newer units vs older ones.
I did not have laundry facilites of my own until I bought a house.
Because you literally need more square footage to amortize all the regulatory required and industry checkbox required bullshit over. Ain't no different than General Motors saying "no more small cars from us in the US".
Hard to draw too many conclusions since "down 15%" is still "way to fricking expensive", but...
Some of us might be satisfied, but zoning and development approvals seems to have a hatred of small apartments. The ones that get proposed meet fierce opposition from locals who are afraid of having too many neighbors who aren’t rich people.