A few times I've left a very big note that says "PLEASE KNOCK LOUDLY" while sitting in my livingroom facing the door just to never see the UPS or FedEx delivery person approach but get a text message about "no one responding" so they reschedule the pickup (and I can't pick it up at the hub a few miles down the road because it's closed...). One time I chased a driver who literally just threw a note on my door (no sign like other time) and very clearly did not knock. I mean I watched them... They just walked up, box in hand, put the note on the door, and walked away. Rushing. USPS also often won't deliver small packages that fit in my mailbox because "a car was in the way" (definitely not true) despite delivering larger packages to my apartment's office the same day/time...
I'm not sure what hell these jobs are that turns drivers into such shitty people, but I feel pretty confident that it is the system turning them into shitty delivery drivers rather than exclusively shitty people applying for delivery jobs.