>Much of the land use for raising animals would not become a lush forest if left alone. There's a reason it is being used for animals and not crops.

With scrub land, that is about the only agricultural use for it. Putting cows on arid scrub land turns useless land into useful land. It's so easy to falsely reason about agriculture when one is so far removed from it.

>What's the ultimate purpose? To subsist using the minimal amount of resources?

That is the ultimate purpose to reduce the standard of living of the poor and middle class.