I'm not convinced that cattle ranching is always or necessarily the best use for much of that land, but I think the second point made was the more impactful one

I'm not convinced that cattle ranching is always or necessarily the best use for much of that land, but I think the second point made was the more impactful one -- "growing animal feed." Much of _that_ land is either land that would be better suited for other purposes, or is land that we're intensely farming at high costs to the environment.