How sad to lose this service after 400 years. People just don't send cards or letters anymore. I am old school and I still send cards to people but use email instead of letter writing. There is nothing nicer than getting a birthday card, engagement, wedding anniversary card, Easter card or a Christmas card in the mail. Then there are formal bereavement cards that people send, an email is not appropriate for a bereavement.
Children especially will miss out on birthday cards unless they are hand delivered or posted with a gift. No money in a card (not that that is a good idea due to theft), there are many people that still write letters and stationary is still sold in the shops. Overseas mail from places where there isn't any internet connection rely on the postal service. This has a flow on effect to stationary manufacturing and job loss that some people have not factored in to this closing of this side of mail delivery.
Postman Pat will not be a happy camper but then he is a van driver, his job is safe.