> Their cost basis for those stocks is their value at the time of inheritance. This way no capital gains tax is ever due on the stock gains

Are you sure that's the way it works in the US? If so that seems somewhat absurd. In Canada there's no inheritance tax but capital gains are realized on death and the cost basis resets. So your heirs inherit the assets and an associated tax bill which honestly makes perfect sense to me (at least for things like stocks).