There are a lot of if's involved. If you can totally free range them (not have to build fences), let them sleep where the wish (maybe in trees or an old barn, don't build a coop and lock them up at night), if you live where there isn't much snow, if you have adequate forage, if they hatch their own chicks and raise them (no incubators and no brooders), if you don't have to hatch a certain number of chicks each year but accept what the broody hens can do, if you have a lot of territory for them to cover, if you are OK with decent eggs instead of trying for double extra huge, if you don't mind eating smaller chickens, if you are not interested in showing chickens, if you raise your own feed if you need to supplement their feed in winter (never buy feed and count your labor as free), if you don't mind searching for nests instead of them all laying in the coop if you have one, if you can handle an occasional loss to a predator, and who knows how many other "if's", they can be pretty free.
By good forage I don't just mean bugs. They eat a lot of grass, weeds, grass and weed seeds, scratch in decaying matter, and eat about anything that doesn't eat them first (do lunch or be lunch). They really like mice, frogs, and small snakes. They love scratching in animal manure, such as cattle or horses, for bits of partially digested matter plus, if they are lucky, maggots. Having a hay loft where they can forage in winter or bad weather can help. With all this they do not need kitchen or garden scraps, our scraps went to the pigs, not the chickens. A manicured lawn doesn't give the a lot of variety in forage, but pasture fields that allow grass and weeds to go to seed or maybe orchards dropping fruit are good.
This is pretty much how Mom and Dad raised their chickens. I can remember losing adult chickens to predators only twice, once a fox and once a dog, though a snake might rarely take a young chick. We did not get much snow, when we did we fed them corn we grew to help them get by. We did have a coop where most of them lay eggs and slept at night, but plenty slept in trees and occasionally the hay barn. It was my job to find the nests not in the coop, some of those were in creative places. While there was some Dominique, New Hampshire, and probably White Rock mixed in with them there was a lot of game in the mix too. Game are smaller, great at foraging, and go broody a lot. I wouldn't be surprised if they were partially descended from the chickens my pioneer ancestors brought with them when they moved into that area in the early 1800's.
There was practically no expense involved and other than growing, harvesting, and storing corn, there wasn't much work involved. The corn was mostly for horses, the milk cow, and pigs anyway, the chickens didn't get much. We'd grind some for corn meal too for us. The corn the chickens got was pretty marginal in the greater scheme of things.
I don't know of anyone on this forum that can meet these conditions or manage these expectations. I sure can't in many respects. I know many are unbelieving, it just isn't possible. For us it isn't. But it is a model for how small farmers kept chickens for thousands of years all around the globe. In undeveloped countries especially, some still do.