From a societal standpoint, we should design a system that rewards the behavior we want to see. No one has given me any evidence that "being born to someone rich" is actually the thing we want to reward in our tax code.
When I look over the top 10 here, 9/10 are on that list from being overwhelmingly self-made and I want what 8 of those have created to exist. (I think lots of other people self-evidently want LVMH to exist, even though I don’t care either way. Same with L’Oreal though that’s also the one that’s not self-made.)
That's a completely arbitrary cut off. Why not look at the top 1, and then tell me that I should extrapolate that out to say that every billionaire is bald and owns Amazon.com ?
Surely you see how choosing top 10 is a completely arbitrary cut off that you invented.
The argument that the top few have self-generated wealth doesn't in any way impinge upon the larger trend of wealth being concentrated amongst a smaller cohort over time.
When asking whose behavior something incentivizes, the answer must always be among those who can influence it.
The possibility of inheritance is an incentive to have money when one dies, that it might be passed on to one's heirs, whose wealth one often values, by virtue of valuing their general well being (as money can be exchanged for goods and services).
It is not the not-yet-conceived who advocate against there being large inheritance taxes.