We should fear a cashless society because there are a lot of things will be changed. I do not know if the economy will become better or will become worse. There should be balance between fiat currency and virtual currency for us to maintain our good economy.
I don't think so, but due to some evolution of technology this cashless sytem will nearly possible to be happen in the futrue, so we have nothing to do about that. And I surely those poor people will get affected for that evolution, but surely there will be a way for them as well.
We should fear some disavantage and this will be a start of new technology that may harm a people because anytime a people can do bad things for the sake of their own wants especially in about money. I don't worry instead i will do my best to keep safe my money and to thibk ahead of the possibility of losing or being hacked.