An excellent source of potassium which is needed by the body.
The industry like all industries, employs people.
Bananas can be shipped from where they are grown to the rest of the world with a minimum of spoilage.
I have not seen the price in our major food stores (Canada) go up in price which is somewhat unusual. (77 cents a pound for I don't know how many years).
People who eat bananas do not get scurvy, so they must have Vitamin C in them. (They do. I just looked it up).
They are high in Vitamin B6 which might interest people who get depression and other diseases.