When your wage depends on numbers of deliveries, I'm not sure I'd be hanging around long either - while not ringing the doorbell annoys me, I bet the reason is they find so many where it simply doesn't work - while they wait and wait and press and press, they can smack the door hard, make the decision to drop and go or not.Very few delivery drivers bother ringing our doorbell at all. It's just a standard doorbell with a ringer in the garage as well as the house.
They all just tap the door and run. Sometimes we hear them, many times not.
On all deliveries, I find somewhere to add a note, or send an email, requesting "please leave in front porch, please. Thanks". Many times, I will hear the bell, or the porch door banged, by the time I've got there, the parcel is sitting neatly in the porch and there's a cloud of diesel exhaust hanging in the road.
Only had one who left 80 quid of oil ON the front porch step in full view.