What figures are you basing your ignorance off of? The majority of the plants humans grow through crop-based agriculture are fed to non-human animals. Animal ag is one of the largest consumers of fresh (ie “potable”) water. There are ten animals living in human possession for every human on Earth. Without intensive plant agriculture, we could not possibly feed them all. Grass and run-off is not what is producing your food.

And since we are specifically discussing the hypothetical suffering of plants, why wouldn’t you count grass? You’re triggered.