And they've given the world a lot of something it wants.

It seems to me that, almost by definition, having $50B means that you've given the world $50B worth of something more than you've taken from the world. Giving the money away is just saying "ok, I don't want to be repaid for what I've produced".

In practice there is a big luck multiple in outcomes. Luck is a factor, for example, in whether you get the opportunity to deliver $x of wealth to customers.