And of course, you could have inheritance tax so that after a few generations, there is nothing left in the hands of the original descendants.
Wealth should be kept in secret and only the wealth you need to spend in front of the society should be declared as income at the spot. Why? Because there is no way to enforce the opposite. Laws that cannot be enforced reliably should not exist at all. I'm pretty god damn sure the Rothchilds family won't pay shit to the government as inheritance taxes. Why should average Joes do that if the elites do not?
Which country or countries are you talking about? In the US, I think the estate tax exemption is over $5M. So unless you own more than $5M in assets when you die, you don't have to worry about it anyway. Afaik, the point of such a tax is to keep "dynastic" wealth in check.