Back in the pre-COVID days of 2019, Sen. Elizabeth Warren (D–Mass.) proposed an annual "wealth tax" of 2 percent on assets for households worth more than $50 million, plus additional surtaxes on households worth $1 billion or more. There were several problems with the idea.
Such a tax would be incredibly difficult to administer, requiring tax authorities to regularly assess and value unusual assets like art collections. It might drive wealthy individuals and households to move their holdings to other countries with more favorable tax policies, as has happened in multiple countries. Most wealthy Western democracies that have experimented with wealth taxes eventually ended them.
