Haven't built enough. You need to build so much that developers are going bankrupt because they can't sell their homes. That's the point where prices come down.

I think most people in the "we built, but prices didn't come down" underestimate the scale of the problem. The (Canadian) population of peak homebuying age (20-40) exceeds the population of peak die-off age (65-85) by about 6 million. If people are still coupling up (not a guarantee these days of later marriage), that's about 3 million homes needed. Vancouver is about 5% of the population of Canada, so assuming no migration to the cities (also not true), that's about 150,000 new housing units. How many were actually built in 2020? 8000.

The city basically needs to get bigger by about 50%, and this needs to be repeated across most of the hot cities in the developed world. What would that even look like? Vancouver, Seattle, Portland, and the Bay Area are basically land-constrained; for them to grow 50% bigger over a decade, you either need a lot of highrises, or every SFH needs to be converted to a duplex.