However, Uber just needs a pool of drivers. They're all completely interchangeable for a given location. This is not the same as a department store - you can't

However, Uber just needs a pool of drivers. They're all completely interchangeable for a given location. This is not the same as a department store - you can't just pull an assistant off the floor and turn them into a cashier, for example. Nor does a department store have the luxury of saying "There are a lot of customers in today, so we're charging three times as much for our goods, in order to get more cashiers in to service them".