When the king takes a portion of my labor 'because he can', then I am a slave. The rich generally understand how to escape the income tax slavery. Let's free the poor.
Remove some of the loopholes for trusts that let people avoid inheritance taxes. Add another tax bracket or two for capital gains. Get rid of the carried interest loophole.
Straight consumption tax (excluding uncooked food) and it becomes very simple to implement. And nobody would file a personal income tax again. Employers would not do payroll tax withholding so wage slaves would get an immediate increase of take-home pay.
The rich understand these phrases: "capital gains", "everyone who files". Those with minimal wage income may not even need to file.
Capital gains are taxed using a different rate schedule, but they are still taxed as income (they are literally included in AGI).
And sales tax and use tax.
Capital gains are assessed when recognized, not like a yearly schedule so rich can defer this and choose when to recognize it. Will certainly take many fun 'business' trips that year to offset.
Remove payroll taxes (which support collection of income tax) and employee take-home pay increases. Employers can stop hassles of the withholding accounting. Employees can stop hassles of yearly income tax filing to IRS.
There would be a temporary increase of unemployed payroll tax bookkeepers and storefront tax prep people. Hopefully they will find something more productive to do.