I think that instead of a wealth tax it makes more sense to change how we tax in relation to the financial instruments the wealthy use.
Capital gains: this should just be income.
Unrealized gains: The argument against wealth taxes are often related to unrealized gains needing to sell blah blah. If you get a loan on your stock value, at that moment the gains should be considered realized and you should be taxed via capital gains (which would be at the level of income tax). Ultra-wealthy use loans against their portfolio to avoid realizing their gains. Make that not possible.
Capital gains: this should just be income.
Unrealized gains: The argument against wealth taxes are often related to unrealized gains needing to sell blah blah. If you get a loan on your stock value, at that moment the gains should be considered realized and you should be taxed via capital gains (which would be at the level of income tax). Ultra-wealthy use loans against their portfolio to avoid realizing their gains. Make that not possible.