Comment by projektfu

Yes, it's complicated because the tax code has been designed for special cases, where there is an opportunity cost to identify and use the special case, but that can be paid for with large enough savings. If hiring that tax preparer/accountant costs $1000 more, but reduces the tax by $1001, then it is economically worthwhile. But in reality, most people are not able to use these provisions and of those who technically can, only a few can use them efficiently.

If you mostly have income from wages, interest, and dividends, your tax is hard to reduce using special provisions and your return is easy to file. If you have a lot of income from business investments, property, minerals, esoteric securities, gambling, etc., then you have more places where you can use these things, and your taxes are accordingly complex.