This is a kind of odd framing. I have children and I don’t see it as zero sum, as in your description. I want my children to do well. I don’t want other children to do worse, necessarily. I don’t care about other people’s children because I don’t know them and I’m not raising them. I want my kids to do well because I have put huge amounts of labor and love into them. The great beauty of most western systems is that they don’t have to be zero sum and they empower individuals and families.
You have projected your bias onto my comment. I do not advocate for an estate tax and don't necessarily support it. And claiming that opposition to an estate tax is an opposition to the success of other people's children is also definitely not anything I believe or claim. Our economy is not zero sum. Everyone can win. Also, redistributive policies almost always fail and waste vast sums while failing.