@TerryD
Your income is not all taxed at the same rate. Different kinds of income are taxed at different rates. So there is no single "Taxable Income Tax Rate" or "simple Federal Tax rate" that applies to all of your income. That's why there are "complex hoops" to calculate your tax.
I'm not sure what you are referring to as "the 2023 Federal Tax Rate Chart" or the "Tax Charts." If you mean the 2023 Tax Rate Schedules in the Form 1040 instructions, note that it says at the top "Don't use [the Tax Rate Schedules] to figure your tax. Instead, see the instructions for line 16." The instructions for line 16 will lead you through all the necessary hoops to calculate your tax. Those instructions stretch over 5 pages, and may send you to other forms.
If you think "It simply shouldn't be this hard" you have to talk to your Congressional representative, not to TurboTax. Congress writes the rules for calculating your tax. TurboTax has to follow the rules that Congress establishes.
I do not work for Intuit. I'm a volunteer in the community. Being designated as a "Champion" means that I have been vetted by the community managers. You can see a bit of my background in my member profile by clicking on the "rjs" at the top of one of my posts.
