Washington state has the most regressive tax structure in the entire country.
If everyone paid the same percentage taxes, then the rich would pay more than the poor because the rich have more money. You would call this "Regressive" even though the rich pay more.
You cannot make an argument that is logical that rich people should pay a higher percentage of taxes, not without throwing out the entirety of everything we know about economics.
"progressivism" is simply socialism, and the real goal is to eliminate private enterprise. IF you can't do it directly, taxing it until it stops moving is the alternative you choose.