I'm interested in those answers, too. I imagine it's much less waste because you can feed the cells just what they need to grow, instead of feeding the bacteria in the guts of an animal.
You ignored the part of the GP comment where they agreed with you. The point is that properly managed pasture increases fertility naturally. We need animals to fertilize, or every plant must be grown with synthetic products.
As I said, concentrated feed operations are bad. That shit should be dispersed in a pasture, fertilizing it.