What are the chances of living in a world with no actual money ? 
Well, fiat money is given out by financial institutions that are big in size and are backed by the government. They make their earnings by charging fees for transactions and they will do everything to stay competitive. So I don't think that fiat money will be gone completely in the near future.
This will not happen,if yes it will take a long time. Cryptocurrencies operate online. Fiat money and cryptocurrencies have different use. What if electricity or internet connection breaks how can we have transactions if all we have is crypto.