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.
I went with a native grass and my watering is down to 1/4 what it was before that. the grass does go dormant and turn brown in the summer/colder winters though, so it's not as pretty but it is what it is, and HOA allows "xeroscaping"
imho that is the only sane way. The water consumption for keeping a lawn green in during the now all so common heatwaves is absurd and really not worth it considering the lawn will be fine once it starts raining again
Many lawns in the US do use grass native to that part of the US. Not all, but many. However grass goes dormant when it doesn't rain for a couple weeks and people don't like that brown look so they water even though the grass (either native or imported) doesn't need it. Likewise people don't like flowers and other weeds and so they apply a lot of chemicals to the lawn - but the grass doesn't need them.
TL;DR: lawns in the US do not need any resources. It is "perfect lawns" that need a lot of resources.
