It’s a mundane act—ordering a pizza, say, on a night in. Possibly the most friction you’ll experience during the next hour is debating with your kids which toppings to choose. You open an app on your phone, you choose your pizzas, and add the drinks. Your credit card is billed. Somewhere nearby, a restaurant begins to prepare your order. Bike-riding delivery people swarm around the pizzeria’s door; one of them is dispatched with your food and makes their way through the intervening streets to