The goal of capitalism isnt the success of the individual above all else. There is no goal per se. The principal simply states that if left alone, the markets will eventually correct themselves, and the true value of an item will be known through supply and demand, and that includes the value of labor. However, humans can never truly leave the markets alone, and we legislate to cause behaviour we prefer. The tax code is an example of trying to legislate behaviour. for instance, why have an interest rate deduction for home mortgages? Because we want people to own homes in the belief that home ownership has other desireable benefits. We could just as easily allow deductions for rent payments, as they do in Canada.
Of course, no country in the world operates in a pure economic theory. Its all a mish mash of what went before plus what we hope will work in the future, along with what some got away with.