Subsistence farming is de facto not a good thing. You can live on licking slime molds off rocks, but that doesn't mean you should do it. Humans are omnivores, and have always raised or hunted animals for food.

Your metric is suppositions about a future collectivized economy. In the world we live in today selling goods at market for a fair value is what keeps small farmers not living a horrid subsistence lifestyle. Farmer co-ops start out as collectivizing family farmers to outcompete Big AG but can end up in the original families just becoming Big AG themselves in a few generations.

We all would love to have some form of socialism to operate under, but we first need to talk about how people operate and produce goods in today's world. Big Ag is not going to go away in our lifetimes, and collectivization efforts like co-ops often end up as problematic as what they are trying to replace. Theories aren't going to put food in people's bellies.