I think that it strongly depends on the country you live in by when the cashless form of payment will take over nearly completely.
In some northern European countries that has nearly happened.
They even accept credit cards in churches or have some kind of ATM there, because nobody has cash in the pocket anymore to give as a donation.

I do not think that it will be the privately founded crypto currency that will be the main payment method.
The majority of the people love their fiat, they will not leave it.