I used to think this was a universal law but then there's Warren Buffett, who's rich but doesn't seem stupid. Of course he's not a tech billionaire.
And then there's Mark Cuban, who is a tech billionaire but who also still seems to have a working brain.
It doesn't mean the money they have couldn't be put to better use serving others.
If there's a law of dimishing return on money owned, the only rational thing is to share with the less fortunate knowing that, say, $5,000 is not even a penny on the ground to you but could feed a family for a year in most parts of the world. Maybe you fed the next Einstein, or helped the next Peter Thiel develop empathy.