Cattle is the most efficient way to produce calories in a dry region in which water rather than land is the binding constraint (Western U.S., middle east, north africa). Crops are the most efficient way to produce calories in regions where land rather than water is the binding constraint (e.g. China, Northwest Europe).
The idea that one is necessarily more efficient than the other as a food is pure B.S. It just depends on where that food is grown.
There is a reason why the societies in the fertile crescent began with cattle culture, and continued to raise cattle in areas where water is more costly than land. Dry areas like that produce scrub and grasses, which is inedible to humans, but edible by cows. That's why we graze the cows in areas where we can't eat the natural crops, and instead we eat the cows. This is the most efficient method, most environmentally friendly method, and is the long standing practice of all societies living in dry regions.
This notion that the peculiar environment constraints that bind in northwest europe bind globally is either ignorance or bigotry.
Really, if they wanted to virtue signal, they should ban cotton, which takes up a lot of water, and is grown in areas that shouldn't be growing cotton. As good a case can be made against grains as against cattle.
This is just bumper sticker virtue signalling and has no place in the business world.