What's not equal about applying the same percentage? No matter your means, the fines are the same percentage, which to me is pretty danged equal when the point is to punish certain behaviours.
If taxes were applied based on total wealth and not income, the two would be comparable. But the taxes you're talking about, income taxes, aren't taxing wealth but the rate of change of wealth, and I can accept that we need to apply slightly different principles in that case.
Make it federal, and have a steep 'exit penalty' for renouncing citizenship if you're over a certain wealth threshold. Make it so that if you try to renounce your citizenship to avoid the taxes, you're left to start from zero again, and if you don't renounce your citizenship, you owe the taxes no matter where in the world you are (and in most of the world, Uncle Sam can absolutely get to you if he wants.)
As a personal example, I left the military reserve because, inter alia, the joy of serving my country mattered less than the tax beating I was taking for being bumped into a higher bracket.
That is: (dis)incentives matter.
Maybe we can agree that our tax system is a Byzantine train wreck in need of reform.