in the united states, there were all kinds of 'wealth' taxes that prevented the loop holes. all that was systematically deleted over the last 60 years as conservatives decided 'me want money, fuck society'
The top marginal tax rate in the US peaked in 1951 at 92% on income in excess of $400k (joint filing two income), the equivalent of about $4.7M in today's money. That should come back.
That or a general property tax to prioritize incredibly wealthy people to prevent grotesque capitalism mutants like billionaires instead of income tax which the working class primarily earns by. We’ve had them before under similar conditions before the income tax along with anti trust suits to break up monopolies.