Speed feels good … until something goes off the rails real fast. You may have noticed something changing in big U.S. retailers without much fanfare. Target and Walmart have been pulling back on self-checkout. Removing ALL such lanes in some cases, and reducing them in others. The headlines frame this as friction versus efficiency. I don’t believe that’s the real story. I appreciate a speedy, knowledgeable, well-trained cashier. I dislike standing frozen at a self-checkout waiting for...