With a better system, we shouldn't have to introduce one-off taxes for "special events" like death because extreme concentrations of wealth should already be heavily and unavoidably taxed--passing wealth to one's children (or anyone else... in any other country) shouldn't make a difference one way or the other.
Estate taxes stir up an irrelevant debate about the morality of inheritance, and puts the government in the role of deciding this moral question for everyone, when that debate isn't necessary and doesn't really matter.
All that really matters is 1 - how much we need to fund the prerequisites for a modern and decent civilization (which includes things like basic income, healthcare for all, housing for all, education for all, etc., imho), and 2 - what is the most progressive, efficient, and sustainable way to raise this money.
I highly doubt the answer to #2 is an estate tax.