Having someone else do your taxes for you, or getting that help from a prepared software package, can remove the opportunity to better understand how your income is taxed. I will readily admit that, were it not for my job, I would almost certainly fall into this group. (Basic math is not my forte, to put it mildly.)
That said, it's worth putting the effort in to understand where your income comes from, and how each different source of income is taxed - not all income is generated in the same way, and it's not all taxed at the same rate either. Understanding even the basic differences between tax deductible and tax deferred, or the difference between investment income, and your employment income, could help you save a great deal of money over time.