Buffet got rich by sheltering his capital gains in his insurance companies.
He also favors the estate tax which takes the bulk of a deceased person's estate and often forces the heirs to sell a business, ranch or farm in order to pay the taxes. That is a twofer for Buffet. Life insurance proceeds when a person dies is not taxable. That encourages people to buy insurance. Also, like a buzzard sitting on a limb, he swoops in and buys good businesses at a low price when heirs are forced to sell.
Buffet is a Leftist predator like many other liberals.