The reason that's become such an issue (here, don't know about the US) is because of the massive, staggering, increase in house prices (and the reduction in the supply of social housing). For the vast majority of people the only asset they have for which inheritance tax is relevant is the family home. Most don't have the multiple valuable assets of the super-rich*.
And with that family home the increase in value is mostly only a paper asset, as the cost of any home the offspring might buy has gone up just as much.
Thus parents feel they _need_ to hand over as much of that value as possible, or the children will have zero chance of finding anywhere to live, and could actually end up homeless. It becomes a self-perpetuating process, and at the same time creates a huge divide between those whose parents owned a place and those who didn't.
A divide that creates resentment that is, maybe coincidentally, very useful for those at the very top. Extreme house-price inflation seems to have a lot of socially damaging effects, because it forces people to run to stand still, even as some imagine it's making them rich.
[EDIT]* I heard somewhere an account of the scheme the super-rich in the US use to avoid inheritance tax, but I couldn't really understand it, and now can't remember where I heard it. Something to do with owning hugely valuable real-estate assets and down-grading their reported value.