> maybe we should change that and have a simpler system with much less complexity

Wholeheartedly agree, but I see the root cause of the issue being income tax itself. As soon as you tax income, you'll go down and endless rabbit hole of what's fair to tax, how much, what kind of income, investment income vs wage income, percentage vs flat rate, etc...

That gave us the mess we have.

I like the idea of consumption tax exclusively (would require an amendment). You're taxed on your purchases.

It's easy to drive behavior (more tax on some things... tax on cigarettes, yachts and private jets) and easy to make more fair (exclude grocery staples).

Consumption taxes are almost always regressive and improperly place the majority of the tax burden on the poor - they're good to have (especially the sin taxes and tax discounts on specific encouraged behaviors) but they should be coupled with taxes on wealth (aka property) and income. And these taxes should be somewhat complex - just not to the extent we have today.