The wealth tax that we should have is a federal property tax, in the form of a land-value tax. A property tax is more enforceable and produces much better incentives than an income tax or capital gains tax or death tax or wealth taxes in other forms.

I think it's underestimated how important ease of enforcement is for taxes and laws in general. Laws that are hard to enforce require more powerful law enforcement agencies, more invasion of privacy, more punishment, more restriction of freedom. Enforcing a death tax, for example, necessarily requires limiting and tracking of all transfers of money or assets between people including personal gifts. A property tax merely requires keeping track of land ownership, which is a function governments already do, and in the worst case you can simply physically go to the land and see who is using it or seize it.