If you had been doing your job properly and not signing for "customers", then the new way of working wouldn't have made any difference.
Nobody pays to have the postie sign for items. That isn't a service we offer (yet?)
If people don't want to sign for things then they simply have to ask the sender to use a different product. If the sender doesn't want to do that it is because they want a signature on delivery and not yours.
Do you forge signatures or use DWS?
This is perhaps why the new product has been introduced.