Just wait until the author visits a small town where people grow their own food and raise their own livestock.
You get a bit of that with Scottish crofters, and I suspect some of the remoter parts of Eastern Europe are only loosely plugged into the Common Agricultural policy, but subsistence farming proper is extremely hard. And of course you can't subsistence farm petroleum.
Really the OP article should talk more about quality, and be slightly less surprised that in a market system high quality (food or information) is more expensive than low quality (food or information). And ask whether the consumers have the same price-quality mapping as the author.
We have no problem getting most of our food locally, and as often than not it's cheaper than the grocery store; eggs, meat, vegetables (I'm in Canada, so not much fruit). I assume this is fairly common outside the urban centres.