What is "fair" requires context. I could argue that nonintervention is fair or that a top-down, Marxist approach is fair depending on how "success" is defined.
It actually reminds me of an essay I wrote years ago called "The Subjective Adjective" [0] (wow, I wrote it 10 years ago!) The premise is that we take how we subjectively feel and then transform it into an objective statement on reality, overlooking how subjective it really is.
Anyways, I agree some of these conversations seem to devolve into definitional debates that may not get at the real point.
I think I also replied to a different comment thinking it was you—identity and conversational continuation, an aspect of context so often hidden/lacking on HN.
In general, I agree with you that a policy could be equal/fair as in giving everyone an equal amount of X, and that the unfair part is where people are in life. I actually liked the idea of charging a flat tax across the US and then having people voluntarily pay the tax for those who couldn't pay it, because I agree, I would see the tax as fair but the wealth inequality as unfair and one way to rectify that is for people to voluntarily rebalance the wealth. But yeah, I'm sure tons of people would see that as unfair.
I really don't know lol.
For taxes, the government provides estimates or recommendations on what a household would owe but its voluntary. You throe your money into programs that you want to see funded.
It could go horribly wrong, but so can centralized planning. At least this way the people are responsible for it either way.