I have not watched or read the news any more. It was said that the refugee of other countries (like in Germany there was a reportage), there refugees in the cafe used bitcoin wallets. The government gave them money and they bought something to buy coffee or food, they just went to the cash register and the person's face or eyes were read using a special camera. He just looked at the camera and she removed from his account a certain amount for the purchase.
So we will rather use the same in the future when taking in many countries a crypto currency. Just just looking at the camera at the checkout.