If done with a residual trust, your estate and anything earned on it becomes essentially tax free. All the smart wealthy people do it. It’s how they don’t pay taxes and pass thier wealth onto thier kids. Do you really think they pay the highest tax rate?
Any property placed into a residuary trust is subject to gift tax if during life or estate tax if at death. It does not avoid any taxes. Gates is avoiding taxes because he’s making donations to a 501(c)(3) charitable organization. He gets a charitable donation deduction for whatever he gives away. If he gave his entire $130 billion to the foundation he would pay no gift or estate taxes.