alt Hacker NewsThe full value of the shares (original basis plus step-up [or step-down] in basis) is already part of the estate and so is already subject to the inheritance tax rules.
It's just that the exclusion amounts are fairly high, so in practice the tax owed is often $0.
Right, the point of the person you replied to was about the scenario where inheritance taxes are small or non-existent - they literally said step up in basis makes sense when inheritance is taxed meaningfully.