It does not help that some of the complications in the tax system are actually intended to make things simpler for most people. For example the 401k and IRA ru

It does not help that some of the complications in the tax system are actually intended to make things simpler for most people. For example the 401k and IRA rules basically exist to encourage people putting money into retirement investment accounts. The idea being that having to account for all the capital gains, divendends, etc would otherwise discourage such investments. But of course the current rules for these are a bit of a mess, with nonsense like the backdoor Roth IRA being possible. another example of a simplification that actually mostly works is the exception to capital gains on the sale of your primary residence. Indeed, unless you get a Form 1099-S or have exceeded the the $250k ($500k married) gain, you don’t need to report the sale in any way on your tax forms. That absolutely simplifies taxes for most people who are selling their home, but it simultaneously makes the tax system as a whole more complex. Similarly there are a lot of weird rules and exceptions over on the business side to try to better align things with Generally Accepted Accounting Principals, in order to avoid the need for businesses to have to keep two sets of books, one for taxes, one for everything else. This adds an obscene amount of complexity to the tax code, especially since not only are special exceptions to the normal tax rules granted for GAAP, but there are a bunch of extra rules intended to prevent specific ways of trying to abuse this. Scrapping all of that could majorly simplify the tax code. But it would actually makes taxes a lot more complicated for many businesses. None of this is to say that all the complexity is there for this reason. There is a lot of use of the tax code to create weird subsidies for certain industries. There is even cruft like some special rules whose benefit to taxpayers is far outweighed by the extra work needed to use those exceptions. Rules defined by court cases that were never codified due to a weird exclusion in the codification, and much more.