Our tax system overall should be more progressive

Tax brackets are the fundamental way that income tax is used regressive: the higher your income, the higher percentage you pay on that (marginal) income

In addition to “income” shenanigans available to the wealthy, the highest tax bracket is at $750,000 (couples filing jointly). While that’s certainly a lot of income, the percentage never goes higher. Someone earning that pays the same percentage on marginal income as a ten millionaire or a hundred millionaire or a billionaire. It stops progressing