Right, I'd love it if someone really wealthy would use the power that wealth gives them to end the power of money in politics here in the USA. But that's a hard position to expect someone to take, especially as we are only talking about a few dozen individuals who can do it, which is why I don't put any hope on it. They'd essentially be crossing a bridge that many before them have used, and then blowing it up behind them, and that won't win them many friends or allies among the elite. And we've seen that Steyer and Bloomberg seem more interested in "saving" the Democratic party from itself first and foremost, with maybe saving democracy and/or the planet a distant second.
In my opinion, being President should be a shit job, one that only those of us with the highest calling to service and duty to the law should ever want to reach for. The fact that already powerful people, celebrities, etc. seem to come out of the woodwork at the possibility tells me we've let the power and prestige of the position grow too much. I don't hold out much hope that the USA will ever go for a parliamentary-style arrangement, but I'm definitely for reforms that revert more of the power of national government back to Congress, and away from both the executive and to a lesser extent judicial branches, and that's something that would be worth spending personal billions on.
I don't read biographies or frankly know or care much about the people in the billionaire class, but it says something that there appear to be very few Gates and Buffetts, and even among those few, there isn't much appetite to rock the political/social boat in any real way. Probably history will look back on their philanthropy regarding malaria, etc. as ultimately more important that an alternative fiction where they used that wealth to save American democracy, but in the heat of the current moment, I too wonder if this isn't a wasted opportunity. Then again, something earned through mass demonstration and consciousness is probably more lasting than something given by the elite.