They're not employees. They set their own schedule. They don't have to wear a uniform. Their cars don't have to be the same. etc.
Fed Ex tried the contractor thing too but it was readily apparent that they were employees and not contractors since they had to follow a schedule that they set, wore a particular uniform, had their vehicles painted to a set standard etc.
An Uber union will do to it what unions did to Hostess, the airlines, the auto industry. Make costs so high and don't give a shit. Look at what it's doing to Illinois, putting the state so far in the red.
Contrary to what people think businesses aren't given a tree full of money when they become a business.