This doesn’t make much sense to me.

Sure. Gates is not a “nice” person. The business practices involved in becoming a billionaire require him to be a vile human being. Granted.

That said, he has given up his place on the leaderboard. He has become dramatically less wealthy as a result of his philanthropic work.

What are you claiming is Gates’ motivation here? Not getting murdered? Come on. There are much more practical, reliable, and cheaper means to achieve that.