I think taxes on financial shenanigans like carried interest, inheritance, and capital gains would probably be more effective than taxing luxury goods. Most rich people don't actually spend the majority of their money on physical things. Mostly they just shuffle it around into various instruments to avoid taxes and maximize returns.
Yea that makes sense. There's around $8.5 trillion of untaxed capital gains. Inheritance tax would be good. Some type of interest tax on unrealized capital gains would be interesting. I still think VAT is still helpful, rich people do still spend money on expensive shit.
They don't address the main issue though. The wealthiest people hide all their money in stocks and then use those stocks as collateral to get incredibly cheap loans.