In a perfect world, if everyone was self sufficient, had ample land and was educated enough to be self sufficient, 'no doctors' may work....on the surface.
IMO, that's how it used to be, and for whatever reason, it didn't work, and humans evolved into farming. Someone will always fall from something and break a bone that requires setting. It's only a matter of time until someone says "hey, I am REALLY bad at growing enough wheat for my family, so how about I fix that arm pointing in the wrong direction and you sling me a few loaves of bread, before you know it we are where we are now.
Cities and farms, cities support the farms, and farms support all those that don't know how to raise beef, sheep, wheat, barley, and straw for out nest boxes hahaha I guess right in the middle is industry too, making all the things that make both tick. I don't say any is better than the other. They all have their strong point and none would exist without the others.
I just fail to see how if everyone on the planet had 1 acre to provide for themselves, how it would really work, I mean, thats how life began.
Don't get me wrong, I love the idea. I wish I had more land and I strive to provide more for my family from my own back yard, but I also acknowledge I am terrible at being a doctor or producing petrol for my equipment, so I would rather pay for it rather than try make my own, or worse yet have my bone head neighbors try make their own! That's a recipe for disaster if I ever saw one hahahaha
Sigh, some day I will have a few more acres and we can have a red hot go at it anyway, the food that is not the petrol!