The money we use today, is virtual already, 1´s and 0´s made by pressing buttons. Some might think that dollar or euro are backed by physical assets, which is not the case any longer. We need a different sort of virtual currency, that is not made by a private institute that takes huge profits and leaves the world in dept(Federal reserve / world bank).
We need a secure decentralized medium of exchange, which is bitcoin and alt coins. last dec-jan when we had a wave of new costumers in the market, there was no infrastructure to support them all and BTC transaction prices went through the roof. The more infrastructure we can produce( alt coins and exchanges with alt coins etc etc) will make an adoption possible, so we wont see a repeating of def 2017 the next wave of as soon as the new wave of adopters arrive. I bet that blockchain and altcoins will grow and grow slowly and hopefully we will have enough infrastructure to support another wave of adopters, if they should come.
I see no reason for money to be eroded that much by alternatives, inflation and devaluation is already here, made by the system it self and how it is structured, block chain will not change that, merely offer a safe heaven for value storage and also work as a medium of exchange when retailers line up to accept it! The collapse of the FIAT system is imminent, block chain is a reaction to the fraudulent FIAT system, and could offer an alternative if we demand it to be accepted, but if regulators have their ways, we will have to wait and wait i guess.
But yeah, you are correct, we need an alternative in order for classic FIAT money to be swapped out!
Peace