Yes I agree with you, but maybe I did not express my point with enough clarity. I mentioned this two species because they count as food of negligible caloric value (sidewalk amaranth is mostly useful because of the edible leaves). As far as I understand, human caloric needs at present population levels require the large scale conventional methods of production (including the Haber-Bosch process). But caloric needs aside, there are populations, which are not consuming enough greens or fruit, even when it grows in front of them. I have seen it in the (warm and tropical dry) countryside here, they think they have to eat lettuce, when they have lots of hibiscus plants growing in their garden. It turns out the leaves of hibiscus aren't just edible, but their nutritional value is similar lettuce (I suspect higher in Mg since it's a lot greener). The answer of some technologists to this problem is to grow more lettuce. Another plant that grows plentifully here certain months of the year is Ipomoea Triloba. I don't think anyone should try to produce them at scale following the conventional methods. In the case of cities I imagine there could be gardens with a synergistic diversity of plants, which try to keep a high total yield, but not a high yield of any specific plant.
Not the original person, but I agree with you. A decentralized food system does not require as much of the distribution network we have, nor does it require scale.
There are food sources that can be had if they were grown local, and grown in a way that makes sense for that locality. By "local", I mean at the neighborhood, and home level. They can be grown synergistically. Even the old, but simple idea of (thoughtful) companion planting can create better yields than monoculture crops.
Our current food system is optimized towards the kind of scale that allows an easier way to control and meter food resources. VCs chase after multiples on investment, and are not incentivized to truly decentralized food systems.
For others following along, there _are_ already people who have guardens with a synergistic diversity of plants. And not only that, have practices that, over time, create yields that require less time to maintain. The permaculture design community have been exploring and implementing these ideas for over 50 years, and people have gotten them to work. They may not have achieved 100% self-sufficiency, but you would be surprised how much they are able to achieve by synergizing not only plants, but also animals, and human social inclinations into the whole system.
Some people here in Australia do pick dandelion leaves and other wild greens, but the general advice (unsure if backed by evidence) is you probably don't want a lot of it in a larger city because of roadside pollution.
I was happy when parsley sprung up like a weed around my house, but it all died out in the drought. Hopefully it comes back soon.
