The only good billionaire

You would not know who Chuck Feeney is, but you know the business he set up: Duty Free. He made billions during the golden age of air travel. I think you could become rich ethically by setting shops in places where millions of people run across 24/7.

the fact that he actually put his money where his mouth was on philanthropy

Even setting aside the question of where the money came from, the theory behind philanthropy is fundamentally anti-democratic. The philanthropist establishes an untaxable trust and personally appoints a board of cronies to allocate limited resources based on an inaccessible group's whims.

I could go into the numerous failures and crimes of private non-profits - the Bill & Melinda Gates campaign to sterilize Africans in a nakedly racist effort to curb population growth, the Longtermist tech industry campaign to invest billions into generative AI in pursuit of a god-like superintelligence, the Catholic Church's enslavement and abuse of young people in their network of church run orphanages from Ireland to Guatamala to Thailand. But the bottom line is that using your economic position to play Sim City with other people's neighborhoods and livelihoods isn't charitable in any meaningful sense of the term. Its mega-maniacal. The utopian visions of the philanthropy's founder don't change that, even if your organization doesn't end up going the way of the philanthropy shaped Ponzi Scheme like Foundation for New Era Philanthropy or St. Jude Hospital's horded endowments