For purposes of this discussion, and most importantly for the tax payer for which this system imposes the most pointless hardship, absolutely, yes, let's get it done. Now.

But. The tax code is needlessly and intentionally convoluted. For a large number of tax payers, you get all sorts of choices on how to file things, how to declare things, what years to declare what, etc, etc, etc. Many of these choices will be based on what you expect to occur next quarter, next year, etc. People in these situations can typically afford to pay an accountant several hundred or thousand dollars a year to help them make the optimal decisions.