He already had enough wealth that he was in a threshold where it wouldn't matter if he got a few more billion if that the was the lifestyle he was willing to lead. There isn't a magical kind of sugar, or drug that's available to a multi-billionaire but not someone with 100s of millions.

If somebody is trying to get billions, they're doing it because they're the type of person that wants to be a part of politicis, and a power player. That kind of person was never going to just give up the opportunity to make more money and gather more power to do more things that they see as neccessary and as good.