Cryptocurrency and fiat money don't has intrinsic value, so the combination of cryptocurrency and fiat money will not give significant advantage. In term of comparison, cryptocurrency is better than fiat money because cryptocurrency is faster, safer and tye cost for maintain it is lower than fiat money. Cryptocurrency should be combined with something which has intrinsic value like gold or silver. We should reduce the usage of fiat then start to use bitcoin as the main of medium of exchange which and also pretend it as representative of gold.