There are “only” 5 possible inputs under Deductions & Credits but 3 of them are categories with several subitems:
Itemized Deductions
• Home mortgage interest
• Deductible medical expenses
• Motor Vehicle registration fees
• Charitable contributions
• Casulty or Theft losses
Other Itemized Deductions
• Other state and local taxes
• Deductible medical expenses (preference share only)
• Miscellaneous expenses
Other Adjustments
• Alimony Paid
• Keogh and IRA contributions
• Foreign Income Exclusion
• Net Operating Losses
I found an article about it here: https://taxfoundation.org/standard-deduction-itemized-deduct...
There are some schemes through employers that reduce your taxable income (for e.g. a scheme to purchase a bicycle tax free) but these are handled by your employer and work by sacrificing some salary in exchange for the benefits.
This results in perverse pressures to make the Federal processes that people are exposed to, such as tax filing, as bad as possible so that voters also hate the Federal government.