Some courier companies do much cheaper shipping but charge redelivery fees because they dont want to have to pay the post office to be a collection point or maintain brick and mortar premesis.
Its fine when you're expecting it and deliveries happen during business hours but its a rude shock when you buy something and the seller doesnt warn you.
Edit: https://www.tnt.com/express/en_au/site/how-to/understand-surcharges/domestic-shipment-fees.html#
Check about 2/3 of the way down. TNT charge redelivery fees because TNT dont take parcels to the post office when you arent home, thats also the reason they charge a residential surcharge.
Ive been doing post and parcel logistics for 13 years now.