They are running out of water though.
Most places in the US get at least ten inches of precipitation annually. Very few get less than that.
With that much rainfall, a lot of homes can be self supporting with catchment systems, grey water reuse, etc.
Edit: Anyone interested in some best practices should look at what Fresno County is doing. They get an average of 11 inches of rain annually and they were basically desert before a canal system was built in the late 1800s.
In some years, their ground levels have risen because of their water policies and practices. In contrast, much of the rest of California and the Midwest are experiencing subsidence as water tables permanently and steadily fall.
Natural Resources Fresno County is unique among California counties in the range of natural resources (forests, riverways, and wildlife habitats) that encompass its vast terrain.... Two major rivers, the Kings and San Joaquin, flow through this rich landscape, providing the County with its most prized resource, water.[0]
[0] -https://www.co.fresno.ca.us/departments/public-works-plannin...
I'm with you on subsidies, but it's worth noting that historically, cattle, sheep, etc. were often raised and grazed on land that wasn't (and mostly still isn't) suitable for growing crops, usually because of some combination of elevation, slope[0], soil, or lack of rainfall. Animals are mobile, so you can move them around on a larger area with relatively sparse vegetation that humans don't consider palatable[1], or even migrate them seasonally on an even larger territory.
So, within some limits, animal husbandry in areas otherwise marginal for agriculture can convert poor ground cover to high quality protein (and other animal products). As long as overgrazing is avoided, this seems to me to be a decent and sustainable arrangement.
[0] Terraces can deal with slopes to an extent and slows erosion, but don't always conveniently lend themselves to large scale mechanized agriculture. Solutions to the other challenges also don't work everywhere.
[1] It's worth noting that the domesticated animal least picky about what plants they'll eat is the goat, many varieties of which, when not moved frequently enough, can completely denude an area by eating plants and bushes down to the ground, climb trees to eat all the leaves they can reach and even stripping the bark, which kills the tree. Which makes goatherding a likely driver of desertification in already stressed ecosystems.
And no, the soil is being depleted of all minerals and life. It’s better to spread farming out.