What I do not understand is why not just implement a more aggressive estate tax on people and close the "trust" and "foundation" loopholes for avoiding the estate tax.
Let's take Jeff Bezos as an extreme example (who isn't even a California Resident). At least until we figure out immortality, Jeff Bezos will die someday. Let him enjoy the wealth that he has earned by creating a company that has benefited society as a whole. When he dies, his wealth should return to the society from which it came. He was rewarded for his work/ingenuity/effort during his life, and now that he is gone, society reclaims the rewards it had given him. What is wrong with that?
The way I see it, once you are dead you don't get a vote, and you don't get a say in the affairs of the world so you shouldn't be able to direct that wealth through any kind of inheritance, foundation or trust. His children have done nothing to earn or create that wealth themselves so why should they deserve any of it? They will have the same opportunities to create and earn wealth that he did, and they will benefit from the society he contributed to.
If they are able to build equivalent wealth via another Amazon.. Great! They earned it! if not that is fine too. You want to help your kids? Teach them how to fish for themselves instead of giving them an unlimited supply of fish.
Passing down wealth from generation to generation or directing wealth long after you are dead through foundations and trusts is directly opposed to any effort to give "equality of opportunity" for future generations.