I don't think that any fair tax will come with agreement on the definition of 'fair' by all sides.
You won't like reading this, but the link shows:
"In 2018, the top 50 percent of all taxpayers paid 97.1 percent of all individual income taxes, while the bottom 50 percent paid the remaining 2.9 percent.
The top 1 percent paid a greater share of individual income taxes (40.1 percent) than the bottom 90 percent combined (28.6 percent).
The top 1 percent of taxpayers paid a 25.4 percent average individual income tax rate, which is more than seven times higher than taxpayers in the bottom 50 percent (3.4 percent)."
The latest IRS data shows that the U.S. federal individual income tax continued to be progressive, borne primarily by the highest income earners.
The problem with the tax code is:
A) It was written by Congress
B) Congress likes to take care of their own and their cronies
C) Low income people don't have the write-offs that would knock off a big chunk of their tax liability, nor do they have the money to buy assets that can be bought & sold without showing a gain or loss. Art as an investment has outpaced the stock markets for quite a while and it's pretty safe, if someone knows art well enough to buy the right pieces. Cars, homes...all kinds of things are off-limits to people who don't have money and that leads to jealousy/class hatred.
If you don't like the link, find another one.