It's a "push" system rather than "pull" that you're thinking of -- the government (in theory) has no idea what someone earned, although they do know how much ta

It's a "push" system rather than "pull" that you're thinking of -- the government (in theory) has no idea what someone earned, although they do know how much tax they've already paid during the year, they pretend that they don't. So the employee's task is to present a record to the government (known as "Filing Taxes") that says: I earned this much, and I already paid this much tax, so you owe me this much back (while it's possible to have paid too little tax, most people pay too much for fear of ending up in trouble -- you're required to pay some high proportion of taxes owed for the year, during the year -- like pay-as-you-earn). Employers send each employee a piece of paper at the end of the year showing how much they earned and how much tax was already sent to the government. For the simpler case, generating the tax filing (form 1099EZ) is pretty much a case of copying numbers from the W-2 onto the 1099. Most people would also need to add some numbers that come from other places (e.g. mortgage interest paid, tax credit for buying an EV) but those are also available as pieces of paper sent to you by lenders etc. Since math has to be done to determine the owed tax and subtract the already paid tax, a paper form is not the right way to do it. A spreadsheet is ok for the math, then copy the numbers onto the paper form. But that's some work. Hence "Tax prep software" which is basically a combination of the spreadsheet and a fillable PDF. Since the government is slow, they never developed that spreadsheet+pdf web site early on, allowing commercial entities (Intuit, mostly) to jump in as an intermediary. Although the US tax system can be complex, as you suspect for most people it really isn't. The issue here is more about the government pretending they don't have the information necessary to generate a person's tax filing for them. This puts the burden on the user, and so in turn they get help with that from companies like Intuit. Eventually it becomes obvious this situation is ridiculous, but putting the genie back in the bottle is not so easy.