More importantly, if I have the choice between roughly equivalent outcomes where one consists of decades of busywork and the other consists of taking a small part of the money and doing good in the world, why in the world would I want to be building a real estate empire?

Of course, for Trump the reason would be because he's a narcissist who needs to see his sense of self-worth boosted by seeing his name slapped onto buildings in giant letters and his face in the news. But for someone who wants to merely lead a good life? You take out however much you need to actually make a positive impact, and leave the rest in index funds.

That said, I'm not rich so I don't understand the system and why things need to be the way you describe. Please provide some insight.