That metric only applies under the assumption that all land can be used equally to feed livestock or for crops. However, humans don't eat grass, and some land c

That metric only applies under the assumption that all land can be used equally to feed livestock or for crops. However, humans don't eat grass, and some land cannot be used to grow vegetables on. There, grazing livestock is one of the few methods available to generate food for humans. Grazing is also better for biodiversity than planting crops.