Wage slavery is just an evolved form of slavery, working out kinks in the former system. For example, it allows the illusion of freedom to exist because we are able to change slave roles within the slave system, and this illusion was necessary to perpetuate the slave system because higher-IQ slaves were needed to maintain a higher level of technology to keep the elites in comfort, and that higher IQ would encourage rebellion if the slaves did not believe they were free.