I don't think it's fair to say the break-up was a failure even if in the near term they still coordinated. In the long term, the oil companies competed with each other. Even if Rockefeller became wealthier, it only adds to the original point: breaking up monopolies unlock value for shareholders and increases efficiency. I highly doubt anyone in the main stream schools of economics would call the Standard Oil breakup a failure. That Rockefeller wasn't punished is immaterial to the breakup itself. The point here isn't to punish Bezos or anyone else. It's about efficiency and fairness. In that sense, that goal was accomplished. No single oil company today wields the power that SO once did.

Also, those guys meeting up together at Rockefeller's house to coordinate would likely be illegal today and probably was back then too.