Granted, maintaining lawns and outdoor swimming pools in a desert is really stupid but you're zooming in on an urban (as much as you're going to get in Arizona) city where land is too valuable to make most farming worth while. If you zoom out to Maricopa county [1], despite the concentrated population of Phoenix, the numbers flip around and about 60% of the water goes to agriculture with another 10% or so industrial with the remaining 30% municipal (though to be honest, I thought those figures would look more like California with an 80-20 split at most).

Maybe if manifest destiny had played out differently and we had planned our westward expansion better all those people in Phoenix and LA would be living in the PNW or the swamps of the south and they'd still have access to Arizona lettuce and California avacados, but that ship has sailed. We can't, as a nation, have our cake by depopulating the west and eat it too by depending on all the agriculture the region produces. When push comes to shove, metro areas will get priority over agriculture and environmental concerns so the entire country is going to have to sacrifice regardless.

[1] https://www.maricopa.gov/DocumentCenter/View/73858/Maricopa-...