It shouldn’t be, and certainly doesn’t have to be. Logically it should be cheaper to live in an apartment than an entire house - obviously.
Suburbs are subsidized by economic centres. And the state of affairs in North America - Vancouver included - is we’re not building housing to match demand. That’s true purely in terms of individual units but it’s also true for types of units. Like apartments that aren’t luxury units, but that can fit a family. They don’t build those anymore because city council makes it completely unprofitable for developers.
If you think that apartment living is inherently more expensive I’m sorry to tell you that you have it completely backwards.