Simply put, the IRS doesn't have the data access Hollywood makes it look like they have. There are timeframes for the Combined Annual Wage Reporting joint task

Simply put, the IRS doesn't have the data access Hollywood makes it look like they have. There are timeframes for the Combined Annual Wage Reporting joint task force to have the data trickle downstream from SSA to IRS. It isn't immediately available to them which is why there is the so-called "PATH Act hold" that stops any returns claiming EITC or Additional Child Tax Credit from refunding out before February 15th each year now so at least some data is on-hand. As long as some payers & employers can still file income reporting forms on paper, they have an awfully long time after April 15th to get those documents in to IRS too.