Somewhat of a real scarcity, as far transport takes money to build and going beyond 1h commute is very problematic, more so if you have kids to send to daycare, preschool or school.

Some of it is alleviated by hub and spoke transport plus extra parking places, but not all. At some point, transport costs split the city into a conurbation, even without the sprawl, you end up with towns linked by capacious public transportation and roads. Or terrible congestion.

There are limits to density after all. Even with walking and bikes and underground and tramways and double decker busses.