My point was the possible disconnect of productivity/yield, and efficiency. A small potato and a large potato likely need the same amount of harvesting work. Now, if you dig up finite reservoirs of phosphorous in Morocco to increase yield in the US, you are not increasing efficiency. That's just planetary debt for a wasteful sprint. I think, in the US this is most evident with water usage, where now many aquifers and reservoirs are spent. Hardly indicative of desirable outcome. Sustainable farming usually has much lower yields inherently. And of course, soil quality and erosion dynamics naturally differ greatly across the globe.