Thanks santafe2, I find this stuff fascinating.

Amazon seems to overlook the trade knowledge of greengrocers, fish mongers, and meat buyers.
Somewhere along the line the good peaches need to be selected from among the average peaches, and a greengrocer is the person who does that.
When real human customers find the produce and meat are poor quality, they shop elsewhere.

The major grocery chains like Kroger and Publix seem to have the advantage. They know the grocery business more deeply than anyone else, while having big piles of cash to buy and install any technology that Amazon stands up.
But betting against Amazon has been a poor strategy. Maybe Bezos really will own the world - all the clothing, all the dry goods, all the hardware, all the food.
One store to rule them all - Amazon.