> I still don’t understand the benefit over a progressive system.
Simplicity and personal data protection. In order to capture tax in advance with perfect estimates, employers would need to know your total income and deductible expenses. With the simplistic system, they just need to know how much they're paying you.
Under the progressive system, there are no surprises or delays, what I paid that month is exactly what I owe.
Like another poster said, effectively an interest free loan to the government from taxpayers.
What am I missing?