I was listening to a rich, US citizen say a wealth tax is beneficial because it would help stop the growth of the deficit.

I noted the assumption that politicians would not use the new revenue to borrow up to ~20x it's amount (at a ~5% interest rate), and increase spending, the deficit, and inflation. "Do you trust any politicians not to borrow against the new revenue and spend?" No answer.

The fundamental problem is not economic, it is political.