Yes, it is all relative, that was my point. Something to remember is that $163B is stock. If some kind of catastrophe happened tomorrow, $40B or more of that could disappear in a flash.
Is Bezos looking for good press? Maybe. Even if he wasn't, some people would think that. And remember, charities don't exactly have stellar records concerning using money they receive as they should. So, giving away $2B even when you have $163B is not simple. I suspect the fund will get a lot more of Bezo's money as time goes on.
It would be interesting to see/know how much philanthropy has been done by everyone with a net worth over $1B. I'm guessing those numbers would be highly disappointing, but I'd be happy to be wrong.
"Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly, and applying the wrong remedies." -- Groucho Marx