Tell me, if the carrier checks the other box on that sticker, who's gonna care? The recipient? "Let me check and see if I received my package. Oh, yes, here it is. It's marked 'Delivered'. I must have gotten my package then."
Maybe it's the sender who needs that information. What are they going to care that the box has been checked? Um, it's been D-E-L-I-V-E-R-E-D!
Most Likely Scenario: The Post Office needs to know if the package has been scanned into the system as attempted or delivered. Still, if it's been delivered, then it's been D-E-L-I-V-E-R-E-D and the post office WILL. NOT. SEE. THE. EVER. LOVING. STICKER. THAT. SAYS. SO.
Just who this information benefits I don't know.
And you wonder why the workers go "postal"? Just ask my sweet husband. Actually he is much more patient with the USPS idiocy than I am. I'd have quit by now! I'm lucky to have such a patient hubby.