Honestly in my nation we are talking about 80+ year old people getting their pension money to their bank accounts and they are capable of withdrawing that with their cards if they want to. Maybe they would have a trouble paying their bills via their app, but they could definitely go to any place and pay with their card.
Nowadays we have cards that you do not even have to use pin for, just touches the machine and it pays automatically, so it's really easy for them. I have to say that the best thing to do right now would be not doing something for the elderly, we will be 80+ year old eventually as well, will we not be able to? We can, so do not lose hope for the current elderly neither.
Technologies are developing so fast, that when current generation that is used to pay just by touching payment terminal with card turn 80+, there will be new and more convenient way to make a payment. And we, wireless payment users, will be considered as old fashioned. But until we have good and services that cost tiny price and shady business, we wont switch to cashless policy.