The really good thing about this is that if we somehow do manage to "ruin earth" and lose a significant portion of agricultural production, we will just have less tasty food rather than starving to death.

Food waste is another kind of "slack" in the food supply chain that would help. Imagine how the world would look if food supply was as optimized as e.g. microchips and then we got any kind of disruption... except now you starve rather than not being able to upgrade your car.