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
Each of the currencies has their advantages and disadvantages. You would not prefer one against the other until you have a problem you want to solve. Cryptocurrency is so much of a choice when you actually want to engage in an international transaction. And I know you are aware that cash will not solve that problem.