In the case of US cities (sorry, I don't know about research that covers Canadian cities) research shows it's a limited supply and failure/inability to grow that makes popular cities expensive: https://www.buildzoom.com/blog/cities-expansion-slowing
Edit: They key section of that study is the section called "Expensive cities and expansive cities"
Edit: They key section of that study is the section called "Expensive cities and expansive cities"