I'm seeing a similar trend in my country where even the culture in city centres is not conducive to having a large family, or a family at all even.

All the parents of 3+ children that I know live in the suburbs or even in the middle of nowhere in the case of one family totalling 7 at the moment, as their firstborn already moved out.

Personally I was priced out of the city where I grew up, so I moved to one that's half the size and live on the outskirts with my family, but in the 13 apartments connected to our staircase we're one of three families and the only ones not renting.