I think some countries use a different tradeoff than the US for their income tax. Instead of spending a ton of government and taxpayer time and effort to accurately assess what each taxpayer owes, the government simply generates an estimate based on what it knows about each taxpayer and uses that. They accept the reduced accuracy but it is offset by the reduced effort in determining everyone's bills. That is to say, you don't need to move away from an income tax to address the problem.