This is a good point. By the same token, most of us have no idea how to milk our own cows or forge our own knives. Having businesses dedicated to one craft and

This is a good point. By the same token, most of us have no idea how to milk our own cows or forge our own knives. Having businesses dedicated to one craft and providing their services to those who'd rather be doing other things seems like a natural model humans - and nature itself - have been following for millenia. It's not like stem cells worry about losing the ability to excrete bile when they become neurons.