No, I'm saying that on a population level, it's rational to assume the luck of the circumstances you're born into, on the whole, is likely to be reflected in yo

No, I'm saying that on a population level, it's rational to assume the luck of the circumstances you're born into, on the whole, is likely to be reflected in your average income over time, and while it's a blunt tool, taxing the people on the higher end more than the people on the lower end is one way to try to mitigate the influence of that good or bad luck and level the playing field.