This meme has become popular on social media, lately. #billionaires #recycling #humor #economics #press
Up until about 1964, the highest income tax rate in the USA was >90%.
Rather than pay that much of their income to to have the government distribute it anonymously, many chose to start giving through institutions while putting their own names on them.
Since then, a few have been motivated to do so for marketing and/or vanity, because there's less financial incentive.