Why do postmen deliver parcels when you're out?

You know it seem utterly fucking pointless to me for postmen to be delivering packages and parcels when 80% of the population is at work. It would save more money to have them deliver early on, say before 8am, and later, say, after 6pm, when most people are at home, and pay them overtime rate, than employ five people to staff a central pick up point 16 hours a day so people can come with their little cards and collect their parcels.

This morning I watched a postman get out a van with a parcel for me, go to my house, find out nobody was in (I was standing across the street watching my bus approaching) then go back to the van with the Amazon package and take out 3 more parcels and not deliver them to several more houses around the corner, then (it wasn't my bus after all) take them back to the van and drive off to another street to repeat the process until his shift was finished and he took them all back to the depot undelivered. It's so utterly fucking pointless, a waste of everyones time and money.

Fuck the post office.