Maybe you mean people like my grandfather? He lived in a town, taught in the local school, and had chickens. He was providing food for them: food he grew in his garden, whatever was left over from his family's meals, and food he purchased. He did not consider himself a "farmer," but he grew a garden, and raised several kinds of animals. He did purchase much of the animal food because he did not have enough space to grow grains or certain other feed crops.
That comes back to the climate question. That poor starving village does not have snow all winter, does it? Chickens that find all their own food ARE possible in some parts of the world.
Also, such videos do not show you whether the people provide some food for those chickens. All they show is that the chickens are not in pens in their owners' yards. (I expect the chickens get quite a bit of food from what the people throw out, whether it is deliberately fed to the chickens or not.)
I don't despise the term forefathers. I do think it is so imprecise as to be almost useless in a conversation like this. My grandparents in one part of the US were feeding and tending their chickens differently than my friend's grandparents in another part of the US, and a few generations earlier the chickens in each place were being fed differently yet. If I trace back far enough, I find my own ancestors in quite a few different countries on different continents, each with their own patterns of feeding and tending chickens.