Because the taxes withheld are just like W-2 withholding...just a crude estimate of what you may, or may not be taxed on when you enter the income in your tax return. The tax return is the final accounting.
You put in the income and withholding on your tax return, the income adds to everything else and a tax is calculated on everything...and the withholding you entered with that form gets added to all your other withholding to determine a final tax due...or refund, for everything.
As an example, if the 28,000 was your ONLY income for the entirety of 2019, then the withholding done on it may have been too much, and you would get some of that withholding back...….but if you had a lot of other income in addition to that withdrawal, then the withholding done may not have quite been enough to cover the taxes assessed for taking it out and you'd owe a bit more (if you other withholding didn't cover it),
Your tax return is the final tax accounting done for all of 2019
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
