I know this is probably naive thinking but I don't understand how we can have so much land and still have unaffordable homes and concentrated populations.
Exactly: it's the policy, it's captured by for-profit industrial complexes - and if you want to get into deeper conspiracy hypothesis, it's also foreign influence laundering $100s of billions into our real estate market, not only buying up/owning our most valuable land and properties, but at the same time making the costs of every Canadian go up and quality of life going down - making us weaker as a society, and more vulnerable to takeover; there's a whole book written on this called "Wilful Blindness: How a Network of Narcos, Tycoons and CCP Agents Infiltrated the West" by Sam Cooper; Canada is one of the richest countries in the world, resource and spring water wise with our lakes, and especially per capita with only 38 million population - we're a prime target, rich and relatively easy, and our systems are clearly captured.
Most of the land is useless and completely unviable for building anything. Seriously.
Almost all of British Columbia is mountain. We flooded many of the river valleys for hydro power in the 1950s. Can't build on the side of the mountain that easy.
Huge swathes of Canada are muskeg bog and tundra. etc.
IMO British Columbia is way under-developed. There is literally 15 or so Switzerlands worth of some of the most beautiful and desirable real estate North of Vancouver that could be developed in similar way to the cities in the Swiss Alps. The Okanogan is not really all that mountainous but is basically unpopulated, etc.
Funny thing about the Okanagan is that given that it's pretty much the only land in Canada where you can make decent red wine, a lot of that land is more worthwhile for agriculture than housing.
Feel bad for the farmers that happened to be born on the wrong side of the border in the US side of the valley. In the USA there's heaps of places where wine can be made and their land isn't worth anywhere nearly as much.