Doesn't Uber ban you if you don't accept almost all fares?

The problem with this models is that you're not really an independent contractor - you're simply on-demand casual labour.

The Internet element makes it unnecessary to stand outside the factory gates every morning, which is certainly a benefit.

But all the obligations remain one way. You have to accept the work, but if you decide to take time out you can be "fired" from the system without notice, at will, at random, and with zero come-back against the "employer."