> Bill Gates is giving away the vast majority of his wealth
That's a tax-avoidance scheme. Here's a recent (and certainly not the first) article laying it out:
https://www.inc.com/geoffrey-james/bill-gates-promised-to-gi...
> You don't know what Elon Musk will do with his wealth
I think we both know that whatever it is, first and foremost it'll be good for Elon Musk.
Bill Gates is giving away the vast majority of his wealth
You don't know what Elon Musk will do with his wealth, but given his track record -- probably something good for humanity