Rather than completely eradicate the sytem and move in a direction that has proven ineffective in every experiment undertaken, why not focus on the problems. The issues become severe in cases where we move away from perfect competition where there are many providers of a good and move towards monopoly or oligopily power structures wehre they can increase prices at a whim...ie, many energy companies.
Up unitl the Clinton years and beyond, the laws in place to prevent market consolidation were used far more frequently. Many of the anticompetitin laws prevented the unfair competition monopoly and oligoploy. It was the kind of thing that led to the breakup of Ma Bell. We do not see much more of that anymore and it is very rare when the government prevents it anymore. There is a need to retake that approach.
finally, the other side of the coin is the increasing loss of ethics and morality. Most successful civilizations fall trap to this and it usually leads to their demise. Clearly there is a need for addressing this type of thing...new ethics laws to be promulgated and enforced to address the greed you speak of. But to put it in proper measure, it is not jsut the greed of the fatcats in Washington, but the greed of us all.