Am Estonian, and from your list only the first one is with physical mail, though more and more people use virtual cards / Apple Pay instead of even owning a physical card. We can also withdraw cash from an ATM using Apple Pay, no need for a card.

As for price changes regarding utilities (or really, anything) we get an e-mail from the service provider or from the landlord (who then gets an e-mail from the service provider). We also pay for utilities via an online bank transfer or automated subscription to the service provider or to the landlord via a bank transfer (who then pays via an online bank transfer or has an automated subscription).

Elderly people set up automatic subscription services in their local bank branch or by calling the bank, I have not heard of a single elderly person using mail to pay for anything.