My wife raised Nubian goats for 20 years. If you feed a milk goat like a dairy cow, they will perform like a dairy cow. That means good hay, and grain, and attention to the medical aspects, like worming, etc. Hoofs need trimmed sometimes.
Our goats were good milk producers, both in quantity of milk, and quality of milk. Do a online search, I think you will find that the milkfat percentage of goat milk might be indeed higher than the milk of a cow. We had lots of cream come to the top, and sometimes made homemade ice cream (mixed with June strawberries - most excellent). They did dictate our time schedule every single day, though. My wife milked twice a day on a regular schedule, so we always had to be home at that time. We would drive as much as 100 miles one way to get our does bred to the best bucks we could find.
In all that time, I regret to say, we never ate a goat - I wish we had. We sold lots of kids to local people, and at the livestock auction barns of which we have 2 or 3 within 50 miles. Earlier this year, I saw a resturant in Monterrey, Mexico that had a number of goat carcases hanging in the front window, and it was a higher quality resturant.
Quite a number of people in this area now raise the Boer meat goats, in fact, the Amish in some areas have hundreds of them. Though I do not follow the livestock markets anymore, I am sure they have a lot more goats pass through them than they did when we raised goats.
My father spoke of his grandmothers goats at the edge of town being the providers of the only milk he and his numerous siblings got to drink in the depression. Makes me wish we still had our goats.
Regarding potatoes, I read that one of the early explorers of Burke's Gardens, which is a high mountain valley in the part of Virginia that is under West Virginia, named the valley that, because on his first visit, he had peeled some potatoes he had with him, and the next year when he came back, the potato peels had sprouted and grown in the rich soil so that he had a garden. His name might have been James Burke if my memory is correct. Beautiful place , if you ever get over that way.