Earlier quoted context omitted.
It’s hard problem that can only be solved through attempts and iteration. The fact that a wealth tax is difficult is not a good enough reason to not try, because the problem of wealth inequality is so severe now.
There are also some things that do work decently well that we don't do anymore for political reasons, such as estate taxes.
There is lots of ways to improve taxes on income and capital gains, but that is really different from a general wealth tax.