>The other 93 percent of the animal’s lifetime diet will consist largely of feed that is inedible to humans, thus not in direct competition with the human food supply.

Just because feed is inedible to humans does not mean it doesn't compete with the human food supply or lead to environmental and resource problems. Take alfalfa, which is one of the most popular feed crops for cattle:

>How much of California's water goes to alfalfa? About 1,000,000 acres of alfalfa are irrigated in California. This large acreage coupled with a long growing season make alfalfa the largest agricultural user of water, with annual water applications of 4,000,000 to 5,500,000 acre-feet.

https://ucmanagedrought.ucdavis.edu/Agriculture/Crop_Irrigat...