The other answers are good. Just to add that If you have a lot of qualified dividends the difference between TT calculated vs IRS table calculated can be huge.
In your example, if the entire 78k income was qualified dividends, then your tax owed would actually be zero because that the tax rate for qualified dividends up to 80k for MFJ filers is 0% ! So when they say that TT can save you money, they are not kidding. If you missed this one detail, you can end up paying a lot more in taxes.
