Your point is was that “you can’t do anything else with the land” - which is flat wrong. We can allow it to reforest. Which is doing something. Your claim that

Your point is was that “you can’t do anything else with the land” - which is flat wrong. We can allow it to reforest. Which is doing something. Your claim that the human population cannot survive on a vegetarian diet is also wrong. The article I linked explains why.