Deja vu.
"Fair" means different things to different people. But the idea that income tax is progressive is hardly a recent development and was baked into the income tax from the very beginning.
Odds are I pay more in taxes than most people here (first because I earn a lot more and second because I don't care enough to try to avoid it).
I'm ok with paying a fair amount more (not just total but percentage wise). If one thinks the government has
any responsibility to provide social safety nets it is pretty much ridiculous to expect all parties to fund that program identically. I think the national park system is a valuable government service that would not be replicated in the private marketplace and if that means progressive taxes to get, I'm ok with that.
But the very question of "fair" is meaningless. Let's say we all paid 18% of our income in taxes. Why is that fair? I'll be paying five times more than my sister. Would I be ok with it if AMC charged me 5 times more for the same service simply because I make more?