My father did mainframe dev contract work for the IRS and once told me it's a miracle you even get your tax returns every year. :) There's quite a mess behind the scenes due to a number of failed new projects at the cost of taxpayer money.

I wish we could automate all of this but taxes themselves are also still a sort of art with all the exceptions. Technically there are rules about when you qualify for things but from my experience accounting firms operate more like law firms in that they help you figure out how to meet the bare minimum to legally qualify for various returns.