Interestingly enough, the DPRK ("North Korea") outlawed income taxes in 1974, calling them "remnants of an antiquated society."
Having a floor that exempts low incomes is probably fine and good though.
Yes, I live in one of them, Washington state. But your reasoning here is highly flawed:
1. Even within Washington, much of society's necessities are paid for by the federal government, which DOES use income taxes.
2. Instead of using income taxes, Washington simply relies on other taxes. Not having income taxes doesn't automatically mean the tax burden is lower.
3. Because it relies on other taxes, the state's overall tax burden is highly regressive*, with poorer people paying proportionately more of their income than richer people. This is great for me, a SWE, but it's a lot less great for poor and working class folks.
* The lowest income quintile pays 17.8% of income to state and local taxes, whereas the top 1% of income earners pay only 3% to state and local taxes - https://itep.org/whopays/washington/
That said, I don't have a problem with wealth taxes for sufficiently high net worth.
Yes they discovered that slavery has lower deadweight loss.