Cash is certainly necessary in the whole society, but as you say our money is always devaluating, it is believed that the encrypted currency will soon take over the model, and at least many people know that the money can be kept in the bitcoin.
This is somehow true. People seek for instant and that is what cryptocurrency can give. All the transactions do in money are easily done with crypto. This is one of the reason why people may choose crypto currency sooner or later no doubt about that. Aside from decentralized market, it has inique features also.