Why not fund the welfare state with a 100% inheritance tax?

The idea that we should be able to pass on our life’s accumulated wealth is deeply embedded. But imagine if we could use that money for the greater good

Source:

https://www.theguardian.com/commentisfree/2017/jul/24/utopian-thinking-fund-welfare-state-inheritance-tax

Indeed! Why not fund the welfare state AND Fukushima Cleanup with a 100% inheritance tax?