I haven't crunched the math or anything, but you don't feed 8 billion people with small farms unless every 10th person is willing to go farm. Currently it's more like every 150th.
Sounds like solid napkin math. It true though, you don't have that happen unless a lot more people are farming and honestly, farming is valuable but the labor is not. Its better spent else where. I absolutely believe there are massive improvements to be made but I think they will happen with technology and more automation.