Hiding identity in digital currency era
I have to go to somewhere and change the digital money to physical money. 


Although that is the current reality, with a few exceptions, it is not the vision of how cryptocurrencies would work.

The intent is that everyone globally would accept your cryptocurrency directly without any need to convert to or from other currencies. 

We can see that the Euro has replaced lots of national fiat currencies in the Eurozone. The dream of cryptocurrency promoters is that at least one cryptocurrency will become globally pervasive to the extent that you never need any fiat currency.