What if the consent is manipulated, extorted or otherwise obtained? When people are brainwashed since birth into the corporation system, and almost all alternatives have been bought up and taken over/disassembled, then the average person has no choice but to "consent" to be exploited by the corporation. Signing a contract might seem consensual, but not when the employer is threatening to starve one's family and cut off one's means of survival.
Perhaps in some utopian future when people have real alternatives to working in corporate exploitation plantations you might have a point - but here and now? Read Richard Wolf.