I think it's an interesting prospect that everyone in the world could garden instead of farm. I'd be hard pressed to find a living space in which one couldn't grow a couple potted carrots and herbs. I agree that high-yield farming is impossible for everyone to do, for space constraints and because people don't have enough time or care to make it happen. I've been thinking of making some herbal infused oils and selling them at farmers markets alongside my modest crop of tomatoes and onions. Has anyone here ever tried anything similar?
There isn't physically enough arable land (27 million square miles on Earth) for 7.6 billion people to all grow their own food. Logistically it would be a problem, as well. There isn't enough room for 7.6b people to live near their plot of garden. (Much less issues like sewage, water, etc.) So the only way to feed the world now and into the future, is with industrial farming techniques. Gardening will always be a pastime effort for people fortunate to live in an area with arable land, and a small enough population that they can have a patch of garden. That's just the way it is. (Oh. And the farmer friend of mine has a business doing exactly what you are talking about: herbal infused oils, soaps, and selling them at farmer's markets. She calls that Soapy Business.
Oh, I have no doubt that it is impossible for every individual to grow all their sustenance. You are completely correct. I was referencing something more along the lines of having a small garden box / a few pots to grow herbs and spices in. I feel as if almost everyone has the means to accomplish this eco-friendly task. It couldn't take more than a few minutes per day to do. Ah! Your friend has a hobbyset I'd very much like to reflect. Do you know if farmers markets charge to set up a table?