Honestly, if we fix the tax code regarding capital gains and loans using speculative wealth as collateral, then all we would need is a one-time wealth tax to even the playing field a little bit, and then a sensical tax code would prevent the wealth disparity from getting ridiculous again.

A recurring wealth tax is not likely to pass, because wealth is static, so it would be taxing the same wealth multiple times. A one-time wealth tax would tax all that wealth that slipped through the cracks without being taxed to begin with, and then an FDR-style tax code would prevent there being a need for a recurring wealth tax.