Right? And also...who needs space between two homes if there are no lawns? Just moosh all the outer walls together.

Come to think of it...that's gonna result in a ridiculously long line of houses. Maybe we could moosh roofs and bottom floors and stack 'em up a bit to make the line of houses only a half to a third as long, and then leave a little space between Consecutive House Stacks™️ - y'know, so that there'll room for more windows.

Partially, even if you got rid of the lawns the houses would still take up significantly more space for both the road infrastructure as well as the houses themselves.

The way i see it is people prefer to fence themselves from the world in their tiny square, rather than enjoy a larger piece of land they have to share.