Crypto-currencies not only stop inflation, they also produce deflation. Money starts to fulfill the function of accumulation which was not 500 years old
That is only true for a coin like bitcoin and other similar coins, but for coins that do not really have a limited supply this is not true but at least if they have some sort of formula to produce the tokens then at least you know the inflation in advance, something that is not true for fiat anymore since many governments are now hiding how much money they are printing.