Power
Just remember, it's only like, one in a thousand pro fighters who reach those fiscal heights.
Even a champion prizefighter isn't going to be anyone's boss, let alone be making decisions about international commerce. The best you can hope for is to gain enough fame that you'll be able to get your message out (if you have one). There are a lot of professional fighters whose true power lies in the cultural influence they're able to exert.
Of course, the main type of power you'll find in this field is more about personal strength than social change. To succeed as a boxer, you'll need to be very physically powerful, and also to have plenty of mental strength along with coordination in order to physically dominate your opponent.