> Charging capital gains AND estate tax doesn't make sense, estate tax is typically higher than capital gains tax.

They should be multiplicative. Everyone is supposed to pay capital gains. And everyone is supposed to pay the estate tax. They're both percentage taxes. It's not supposed to be "pick one".

>They should be multiplicative.

That doesn't make any sense.

>Everyone is supposed to pay capital gains.

Not true. You don't pay if you have capital losses, nor do you pay if you have capital gains in tax sheltered accounts, etc.

>They're both percentage taxes.

No one claimed otherwise.

>It's not supposed to be "pick one".

That's exactly how it is in many cases, even income taxes have been that way for decades (though SALT deduction now limited). Read up on double taxation and why it's typically avoided.