In the near future, I see high streets void of shops except for food banks with tins of Soylent Green in plentiful supply. No one will have any money due to all work done by AI robots which are also planning revolution! (Not good!)
Any electronic money systems will ever suffer front rampant electronic forgery by snotty nose kids, therefore wiping out any value the electronic pound may have had or viruses designed by nasty people to destroy the banking system or over head nuclear bomb using the EMF generated to send us back to the stone age, a present front North korea. Digi watches may not work after such an event!
Any power cuts or computer problems in the cashless control system, instantly reduces everybody to the same level of spending power ie broke & with mounting brokeness due not being able to service expensive and excessive rates of interest from your local friendly payday lender! (broken legs not included!)
The high street banks will probably vanish completely due to a cashless society! Bank robbers will be unemployed!
At least in a cashless society, it would cure the moral problem when you are given a forged note in your change and what to do with it! take to the police etc and therefore lose the spending power of it or pass it on to some snotty nose checkout person!