alt Hacker NewsWhich still doesn't have anything to do with whether it's income or sales tax. If someone has some money they're not intending to spend anytime soon then they put it into a 401k to defer the taxes, or any of a dozen other things that have a similar result.
Sure it does. There are caps to those tax advantaged savings accounts. There's no cap on not spending money.
You're still designing a system where the highest effective tax rates are paid by the lowest income people and the lowest effective tax rates are paid by the highest income people. You've pointed to nothing that changes this truth.