“Seems like the IRS could audit every electronically submitted return. It would take a fraction of a second for them to read it in and another fraction of a section to compute the totals and verify them the from the tables and employer records.”
indeed, that is in fact exactly what is done for ALL submissions, though obviously electronically submitted ones don’t have to wait for the extra data-entry step of the IRS converting paper returns to electronic ones ...
However, those automatic checks are not audits: the IRS computer checks are simply looking for various errors relating to mismatches between the return and the various W-2, 1099 and other income related data submitted by payers to the IRS, as well as data entry, logic, and mathematical errors that mostly occur on paper returns ...
It is to the IRS’s advantage to have the returns submitted electronically. Seems like an astronomically huge task to manually enter all returns of all of-age Americans into a computer database.
Again, just saying that the IRS would be able to check a return in a fraction of a second if electronically submitted vs an hour or more if submitted as paper; even longer if it is handwritten (which is also legal).