Granted, the market had ramped up so quickly, and then crashed so fast, that the number of underwater mortgages was likely small – and probably haven't come up for renewal yet. So, you're right that there isn't much management experience, and may never be.
If you cherry pick the localized data, even the worst off suburbs of Toronto you see a dip of just over 22% with a pretty quick reversion to the mean. If you look at metro areas, none of the cities in Canada saw greater than 10% drops from 2022 peaks, and they have all recovered from the bottom.
If you break it out into type of home, it shows that the average price drop is about ~10% for any given market. This shows that consumers in 2022 shifted buying preferences from expensive home types to cheaper home types. This makes a lot of sense given the push for multi family housing and rising interest rates.
The value of individual housing didn't change 30%, it was mostly just a market shift towards cheaper housing. If people shift from buying Mercedes to buying Kia, the average transaction price for a car will fall a lot, but that doesn't mean that Mercedes is on sale for cheap.