> it's not all that hard to file your own taxes the old-fashioned way
> Each time, it has taken me a full 12-16 hours
You have a strange definition of "not that hard".
This is exactly my experience trying to do it the old fashioned way. The IRS's documentation is written in accountant speak so deciphering what each means is an effort and all of the time it takes adds up. Who else uses the word "schedule" to mean "form"? And then there are so many places where it talks about "qualifying" this or that without telling you how you know if something qualifies.
And that's before you get to the nightmare if you own stocks. My wife inherited some telecom stocks from her grandmother. Her grandmother got them as part of her paycheck when she worked at AT&T. Unfortunately she didn't keep any of the original documentation for them (my wife had to track down the stock management companies and get them to reprint the certificates). These stocks were then of course split across all of the baby bells and merged and split a ton of different ways over the years. Then one of the companies merges and we get a payout for a fractional amount of a share and have to calculate the strike price of the stock for the sale.
As an average person this seems like an impossible task. We just enter 0 and pay a ton of extra tax because how in the hell are we supposed to do that calculation? As far as I can tell we can never sell these stocks.