Rice is not a luxury for most people. It’s a staple. It uses ca. 40% of all irrigation water globally. Also cotton is not a luxury, though it also uses quite a bit of irrigation water.

But normally they grow rice where there's abundant water. There's no shortage of water globally, it's just not always where you want it. Like they want water in the middle of the California desert to grow crops.

Rice in Pakistan, northern India, Mali, Calif., US irrigate their rice because rainfall is insufficient. Cotton grows in semi arid regions as well.