Earlier quoted context omitted.
Don’t water the lawn (or fertilise or roundup etc.) in Australia: for some reason it stays green without it: buffalo grass is as tough as nails! Sometimes it goes yellow but it always comes back!
Lawns in the US consume as many resources as they do because the typical lawn you see isn't a species native to the US, instead it was imported from Europe. With the soil being different etc., it is not surprising lawns, especially when they're as big as in the US, require so many resources.
TL;DR: lawns in the US do not need any resources. It is "perfect lawns" that need a lot of resources.