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

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.