The problem is competitive market forces, uber does not increase the number of people who want rides enough to offset downward wage pressure. Supose you work 30 hours a week for minimum wage, uber unlike most jobs lets you back fill even sub minimum wages after costs. So now those workers displace people unwilling to work random shifts as needed and taxi drivers who can work below minimum wage creating an ever growing downward spiral.

In the end when one player gets to ignore the rules they will do so making things worse workers industry wide.