There are lots of people who don’t think a flat tax on income is the fairest tax. Presumably a person whose income is very large has a lot more to lose if society collapses so they should pay more to maintain society. I tend to believe progressive taxation on income/wealth is the most fair. But I’m someone who believes that there should be a ceiling and a floor on how much a person can have. The distribution of resources and wealth in the world is grossly unfair in my opinion.