There aren't very many historical examples of societies with high income tax, mostly because being able to effectively collect national income tax is a fairly n

There aren't very many historical examples of societies with high income tax, mostly because being able to effectively collect national income tax is a fairly new invention after all. But the examples we do have include USA in the 1950s (top tax bracket 91%) and Sweden in the 1970s (top tax bracket 87%). Those are some of the most successful societies ever, especially in comparison to their peers at the time. Even the extreme right in these countries sees those eras as national high points. I don't think there's evidence that taxation on its own creates stratified societies of super-rich and super-poor. For example, the problems of Brazil are largely unrelated to the tax rate.