The complexity of these forms combined with the fact that getting them wrong is a felony means that filling them out without any help is out of reach for the vast majority of the population.
Getting them wrong isn’t a felony. Refusing to pay after they inform you you were wrong might be a felony.
But they won’t tell you you were wrong for a few years, during which time interest accrues.
(Source, just paid 5k in taxes+interest for the 2021 year after IRS sent me a letter saying my stock selling profit calculations were off by 4.5k. I think they were wrong (I was certainly wrong too) but I can file an update and get a refund on my next taxes if so. Better to stop the interest accessing while I figure out my bases)
Why do people keep repeating this? It's so obviously wrong I can't believe that saying it can be anything other than bad faith. I have miscalculated my taxes twice now: in both cases, the IRS sent me a letter explaining the mistake and what I still owed, I wrote them a check for that amount, and that was it. No "felony" or even the faintest hint of one was in play. The letters even had an apologetic tone and suggestions for how to set up payment plans, as well as multiple ways to dispute the charges.
Because it satisfies their narrative that you're basically forced to use tax prep (human or machine) to file and therefore the fact that you can actually do so for free is a false choice.
It might be similar to the inverse of xkcd.com/1043 (Ten Thousand), in that something has been repeated so many times people believe it to be true. Thinking about this more I'd bet the myth that miscalculating your taxes was an exaggeration based on anti-tax rhetoric.
But they won’t tell you you were wrong for a few years, during which time interest accrues.
(Source, just paid 5k in taxes+interest for the 2021 year after IRS sent me a letter saying my stock selling profit calculations were off by 4.5k. I think they were wrong (I was certainly wrong too) but I can file an update and get a refund on my next taxes if so. Better to stop the interest accessing while I figure out my bases)