> Well, no. The family in which you are born is effectively random.
I've seen some screwed up ideas on what "random" means before, but... c'mon.
It's not random in any meaningful sense of the word. There are some uncomfortable truths that must be dealt with here, but to hide from them by saying that some arbitrary individual might've been born to a different family requires purely decadent levels of denialism.
> We can have a system that optimises for medium-size companies and businesses
We can't. Because even the tiniest businesses and farms are already multimillionaire levels. Medium-sized are far larger still. If you set these taxes to avoid harming those, the thresholds for taxes to be applicable would be so bizarrely high that we'd all laugh and shake our heads.
Inheritance taxes are tools designed to teach the middle class to not bother trying, because the lifetime it would take to accumulate enough wealth to set the grandkids up to do well will see it all taken by the state. They're harmful to the middle class, and not the billionaires.
The billionaires are still young enough to find some place or mechanism to avoid the inheritance tax. They're beyond it. It's the lesser folk that can't avoid it. But I guess it's not all bad, even if your great-grandchildren have crippling levels of student debt, at least they can sleep well at night knowing that it helped purchase JDAM bombs for Sudanese weddings.