Chinese chains Luckin Coffee and Mixue are coming for U.S. customers, because U.S. companies taught them how

Last week, I whooshed into a Luckin coffee shop in Lower Manhattan, snatched my mobile order off the counter, and was back on the street within eight seconds—as if I’d run upstairs to grab my keys. The fact that this required zero human interaction barely registered, especially because I was too giddy about the deal I’d scored on the app. My iced coconut latte cost a mere $1.99—a full 69% off the regular price, after I used one of the six active coupons that appeared on the screen. I had o...