Across my working lifetime, even with many of those things at some point in time, most years the IRS has (or can obtain) everything they need. Heck, nearly 90%

Across my working lifetime, even with many of those things at some point in time, most years the IRS has (or can obtain) everything they need. Heck, nearly 90% of households take the standard deduction. The IRS should send a pre-filled form with an amount owed (in either direction). If you agree, you sign it, and make any payment/refund. If you disagree, you add your deductions and whatever else needed, similar to today.