Almost every country with these problems has similar symptoms and the problem could've been seen coming from decades away. Tackling these things requires far, far more input from governing bodies. Input they aren't willing to give.
This leads to people who rabidly defend the systems that increase their property value, and these people also tend to be the local voting majority, so they can shoot down anything that they don't like.
The solution is declaring emergency powers to use eminent domain to seize unused property and build medium to high density housing on it. Yeah we'll have a few 6-fig account managers handcuffing themselves to bulldozers, but eventually it will get through.
Basically the government is turned into the sole buyer who can also ignore zoning and resident complaints.
That said, it's nowhere near the sole contributor. Quite a few countries have very low immigrant numbers along with low birthrates and still face soaring house prices. Rampant individualism doesn't help, either.
Very few voters actually care to solve the issue. Home owners still far outweigh those who don't. Quite a few of the older generation bank on their property/properties to carry them through retirement. No one wants to see their house go under, even if they can realistically endure it without severe consequences. There's no incentive to increase interest rates, but banks obviously don't want to carry more risks, so individuals aren't getting the same mortgage-to-house price ratio as before.
"Figure it out" mentality. Even if there is a national or even global trend, responsibility to solve the issue is pushed onto the individual. Or worse, global mentality shifts to accept what is going on. "Yeah buying was normal back in the day, now you rent. Get over it."
Grandfathering and "empathy for the fortunate". Yes, I get it, you don't want your lucky uncle who worked a bad job for decades to lose his retirement. You don't want Mr. John in his McMansion on the other side of the road to lose his fortune. Almost no one wants to be the bad guy. Yet special ruling to keep the "haves" in their position continue to be placed at cost of the "have nots". No one wants to hurt anyone. As a result, the solution often seem to be continuing the same fruitless endeavor which changes nothing for the "have nots".
As mentioned before, population has yet to peak. Governments are still incentivizing people to come in or reproduce above replacement rate, despite it becoming evident we're just not capable of handling them. In theory we can handle way higher populations. In practice, there's no incentive to do so without severely punishing the working class further.
We're slowly normalizing a cyberpunk dystopia and most people seem okay with it. "At least you have iphones" is going to define gen Z and gen alpha at this point.
This is a symptom of neoliberal ideology - the acceptance of any market outcome, no matter how negative, as "natural" and to be accepted or at least left unchanged. That's the predominant narrative, but I think that could change. The reason I have some hope for a social-democratic turnaround is that the US has cultural hegemony, what happens there is broadcasted across the world through American media and other cultural exports. Currently, younger generations are engaged in a revival of left politics; this will almost definitely influence American politics in the coming years, and I'm hoping us Europeans (I'm from the UK) see some downwind benefit from that. There's already some smatterings of progressive politics in the UK, for instance - probably on a level comparable to 2012-2016 in the US. We even had our own Bernie in the form of Corbyn, and our far right resurgence is running low on steam thankfully.
At some point the market decides this, if inflation persists. BND (NASDAQ) is already down over 9% YTD and that's supposed to be the safe half of split stock/bond investing.
Despite how some people seem to view the Federal Reserve (and whatever the central bank of Canada is) neither country is a full on centrally planned economy, at least not yet.