I was stuck behind someone in a queue the other day. He got his phone out to pay for his shopping but had no juice left. He then took his rucksack off his back and started rifling through and took out a portable charger. It had not juice left He then began digging around the rucksack again and took his wallet out. He pulled a card from it and tapped the reader. It didn't work. He tapped it again. It didn't work so he slotted the card in the machine and tapped his pin number in which worked .
If he'd had a tenner on him we would have both been halfway home in that time it took with all that faffing about. So much for a cashless society and smart technology