Yes, without getting into all the practicalities (and there are many deep dives into all of them), the general argument is go ahead and get rich off a mixture of your luck, work, and all the benefits that society collectively owns (well-educated workers, roads, etc etc etc) and enjoy it. Be a multi-millionaire. But after you die, whatever is left goes back into the common pool for all kids to have, for example, savings accounts that they access when they are 18

What about non-monetary inheritance? Even if rich kids don't inherit anything, they can still get advantages from parental connections, educational opportunities, genetics, etc.

I think zero inheritance is probably not gonna work. You'll just incentivize a black market (think jewels, cash in mattresses, gold, whatever...people will get creative). You want to find the level where the benefits outweigh the costs. That's probably some significant amount of inheritance, but also a very hefty tax. I don't know where exactly it is, and it'll probably vary with a lot of factors.

As someone who generally agrees with the poster you're replying to, yes I would be in favor of a 100% estate tax

Bingo. Rich people deserve the riches of their birth, but poor people be damned.