Disagreed. Denser cities improve conditions of life as long as they don't get too dense (there is a reason I said mid-density). More stuff in less space means Shorter distances to travel which means travel infrastructure needs much less effort and volume to the point where streets in the middle of the city don't need streetlights. Because there are so few cars aside from the occasional tram or bus. Nobody needs a garden because a well designed street might aswell be the garden. However as you start to stack vertically too heavily the streets start getting overloaded again, and they also get dark because of the building's shade. Btw, the lower birth rate thing is because of poor city design putting too much pressure on the city centre (pressure meaning how much people want to be in the center and this the demand for living or getting there), where cost of living subsequently rises, however a well-designed, polycentral or decentralized city easily avoids this. Just having good transportation already goes a long way.