The IRS wants to be the one to figure the taxes owed by us average Americans, and the IRS wants to do the figuring based on the data the IRS claims to have collected on each of us average Americans.
The Inflation Reduction Act, that travesty that too many Republicans actually voted for and that is a source of the present inflationary environment (among a number of economic problems inflicted by the IRA), authorized the IRS to explore the concept of a mechanism that would have the IRS figure our taxes for us.