Where are the Scrooge McDuck money bins? The money is invested. Or it's spent and someone else has it.

Inheritance tax is a double tax. The money was already subject to income tax, capital gains, property tax, sales tax, etc. If the problem is that capital earnings accumulate faster than labor earnings, then we should just address that problem.

Property isn't about what it does for the rest of society. Property is a human right. Taxes generally are on voluntary actions for a reason. You choose to purchase something, own taxable property, emit carbon, etc. People don't choose to die, so it's an involuntary tax, something we should think about.

Lots of people don't care about the ethical implications for personal reasons, I guess, and that's their prerogative. But there's no moral high ground on not caring about the ethics of property rights.

You act as if all inherited wealth is just sitting in bank accounts. Some is, some isn't, some heirs are active in and good at business, others aren't.