From Financial Times:

A driver also plays the implicit role of conductor, ensuring the car is fuelled and hindering illicit activity. Driverless cars will have to be serviced and monitored to do the same thing. “Driverless does not mean humanless,” says Ashley Nunes, a researcher at MIT. His work on the subject has concluded that robotaxis can’t compete with the gig economy on price. “Robotaxis replace one set of human costs, the human driver, with another, inefficiency,” he adds.