What are the reasons, why people use Cash or Credit Cards / ATM / Banks?
* Work offline 100%
* No fees.
* Accepted for Food Shopping & Micropayments
* 0 confermations time
* 0 exchange risks
* anyone is able to understanding of the value of payment
Yes cash works online and have no fees but it has his limitations, you can not withdraw big amounts and you have limits when you travel so you are very limitated and another think you did not mention it is inflation which makes you loose value every single day. To store big amounts of cash it is not easy too/ not safe.
I think it is more better to use bitcoin instead of cash for online purpose. In fact bitcoin is the best option to be use for online purses where you do not need to change your bitcoin into anyother crypto currency. you can use bitcoin in all over the world with same value.