Neither ... because politicians aren't interested in a flat tax.
The main reason the tax codes are so complex, is that it is impossible NOT to violate them. So if the government is "out to get you" and can't get you on any other crime - it can get you on "tax evasion".
And no, that's not paranoia. It's reality. Clinton used it to investigate an author he didn't like, in the form of an IRS audit every year during his 8-year term. Thankfully, the author could afford a "big name" tax attorney.