Cash will stay, not everyone is well-versed to technology and it will be a long process until the whole world goes digital. But the first one that will adopt the cashless system would be the first world countries and countries that has means of living through technology and is currently have a big GDP through technology and products related to it.
In Asia, China is making a cashless society and in Europe Sweden are following their steps.
In China, this is true. Alibaba is like the Amazon of China and they're one of the biggest payment system that's being supported by their government.