not valid when the masters can also be live-in servants for the slaves (e.g. the uber driver can hire a freelancer to build a website for him, and the freelance

not valid when the masters can also be live-in servants for the slaves (e.g. the uber driver can hire a freelancer to build a website for him, and the freelancer can hire the driver). Right now it s usually low-paying work that gets commoditized heavily, but over time it will happen to everyone.