The YouTube video linked in a reply to the parent comment does a good job of explaining but the short version is that he signed over the company to a charity that his family controls to avoid a tax payment.
There’s basically nothing charitable about it because it literally enshrines political power within his family forever as the charity structure allows political donations to be made through it.
The video also makes the point that you can never accidentally find yourself a billionaire. At some point you’ve fucked people over to get and keep yourself a billion+ dollars.