Let's start with an MVP then.

For federal taxes, the government takes your W2 and 1099s, and prepares a tax return, with the standard deduction. If you either know you have a complicated federal situation (and people know if they do), or think you can do better with itemizing your deductions, then you have the option to do it differently.

Then, iterate every year to make it a little better, until 96% of people don't have to think about it.