The problem with going cashless is that not many people will be able to embrace it. in the advanced countries this may not be such a big deal as nearly everyone is already familiar with all sort of technology and buying online in a cashless manner. in the developing countries with high number of uneducated people, this can be a very big issue, it will require teaching almost everyone on how to operate an internet enabled device and own one as well.
Going completely cashless will pose a lot of challenges to many people which i doubt the governments are ready to subject its citizens to. So this is not advisable best thing for now is operate in both ways
I think there is no real problem embracing a cashless policy as it brings more convenience and fast, and efficient transactions. But the only problem is, the government is not ready for it. The majority still prefer the traditional payment system, particularly for those old and uneducated people as they find it hard to cope with the changes. I think the best thing to do is to offer both cashless and traditional payment system, and its up to the people what to choose for their own convenience.