I worked in nonprofit development and as an executive for multiple organizations.

I can't speak for EVERY foundation but founding a personal foundation is an easy way to avoid taxes. On their website Hue Jackson's Foundation posts a crude annual report that shows 95% of the funds come from Hue Jackson. No shit, he's avoiding taxes.

It's always an easy way to receive payment for appearances by also avoiding taxes.

Almost every celebrity has a personal foundation for these reasons and usually they are rarely known if every publicized.

Remember will Bill Gates vowed to donate his wealth? Guess where that money went? Into the Bill Gates Foundation. Guess what he did with it? Purchased a ton of stock and is influential of corporate decisions. But he doesn't own the sock and he doesn't have to pay money on the capital gains AND he gets tax avoidance on his own income.