This is certainly true for most people, especially those with jobs.

But for business ppl, the IRS can’t figure it out without having all of your data (revenue, expenses, etc…) so it would be a dystopian nightmare if the IRS could tell you what you owed in advance.

Instead they trust that businesses will pay their fair share (which they largely don’t) and audit a tiny percent of lower income earners and squeeze more pennys out of them while the rich (who have the power to influence them) escape any real accountability.