I mean, just bigger apartment is also solution that doesn't have that much of an environmental impact (the space "wasted" is saved by less office buildings).
Additional space in a city is significantly more expensive than the same space in the suburbs because each square foot is in much higher demand.
Some people like the suburban lifestyle, but the reason even people who prefer the amenities of cities move out is that it's the only affordable way to get a lot of space.
The solution is vastly more urban construction to meet demand, but development and regulatory changes have been slow.
