There's some theoretical possibility that a billionaire could be a non-sociopath. If they literally dedicated their life to extracting money from the wider economy or top crust, not spending any of it on themselves or their descendants, but instead solely redistributing to the most needing people in the world. Monetary wealth at the end of the day is just economic control - it doesn't become evil until it's actually used for your own benefit, i.e., the economy is being rewired for you to live in luxury.

Assuming of course (big fat assumption) that you don't screw people over to get it in the first place - and, even if you are giving it all away, it's questionable why you'd end up with a surplus of money that large, if your goal is to donate it, why would the rate coming in exceed the rate going out, unless the goal was to purchase some institution or something, i.e., purchase Walmart and turn it into a cooperative. Probably not to invest the money to grow it to have more to give, because the return on investment for the money also has to come from somewhere, i.e., has its own ethical ramifications.

But I mean, name a single person in the last century who fit that profile. I can't name one. So.