[[[[[[[.....That wasn't around 40 years ago that you feel is a vast improvement over the way 'grandma' did it? Such as better feed, DE, automatic doors, electric fencing, etc......]]]]]]
Sorry to be the one to disillusion you, but 40 years ago, we had better feed, electric fencing, DE, stock tank heaters, electric incubators with thermostats, and you could have gotten automatic doors, if you wanted them, but nobody thought to use them with chickens.
In my opinion, feed was better. It contained animal protein and less byproduct junk. Chicken wire was immensely better quality. It was made in America of American metal, and was cheap and strong and it would keep out dogs and coyotes as long as you stapled it down to the framework well.
People had organic gardens. You could buy organic food for people, but I don't remember any organic commercial chicken feed. However, people who believed in organic did raise organic chickens and eggs, and they were really organic. Mother Earth News organic, not Uncle Sam's lackadaisical definition of organic.
Not many people kept chickens as pets. Occasionally, a special bird would get elevated to pet status, but not the whole flock. So there were no chicken diapers. The thought of an indoor chicken simply never crossed anyone's mind.
I don't remember any Cornish Cross chickens 40 years ago. The bargain priced chickens in the market were small birds with slim breasts. So Cornish Cross chickens are an improvement. Computers are a huge improvement. No computers back then. No wait. About 1971 or 1972, friends were talking about getting a computer. $5,000, and it could balance your check book for you and not much else.
I can tell you what was way better back then: price of gasoline. I was paying 25 cents a gallon for gas. But 40 years ago was not Little House on the Prairie.