I have always thought of subsistence farming as sad, and then Paul Theroux in his book the Dark Star Safari alludes or says comments about how the persons now have no food because they stopped the subsistence farming.
However, subsistence business is the way of the world, in a country where you can start a business anywhere, on any corner, and as you wish. Everyone desires to be self-employed.
Subsistence prepaid cell phone card or loading is rampant presently in the world, everyone is in the same business, and nobody is making money, then with the trend of cell phones, they spend money they do not have.
In Mexico, there is or was a convenience store or shop in front of every home. It was a subsistence shop, no money, dreams of money, but no money, and the completion was fierce, and their children ate all the profits.