Bezos doesn't sell stock. What little he does goes into Blue Origin and is written off again. When Bezos needs cash, he just borrows from the bank using his shares as collateral. No taxes.
https://www.forbes.com/sites/rachelsandler/2021/05/11/jeff-b...
At least that’s the model as I understand it.
If you completely ignore estate taxes, this would be true.
I think that kicks in after $20M?