https://ourworldindata.org/land-use-diets

What you say is maybe true but irrelevant. We don't have to grow grass.

Crappy grass is the only thing that grows in the upper plains because there isnt any water.

Asserting ruminants are “irrelevant” tells me nobody should take you seriously on this topic. Replicating their function is the problem to solve if you ever want to make the case you think you are making.