The response: it makes rich people richer!
With cryptocurrency, we can avoid influence of government and make a currency using any rule we want. For example, Bitcoin count is limited and that makes the currency deflationary, in other words the currency value is supposed to increase (so price decrease) with time because while user count increase, coin count does not increase.
So, people who own a lot of BTC, just have to wait to be richer. Anyway, anybody who hold BTC get richer :)
In other hand, ETH will swift to prove of stack, in other words, people who have a lot of ETH and can stack them and get reward: rich become richer
There are plenty of currencies, but when you choose one, anybody will naturally choose the currency which will make him richer. This is good for people who have money, but if you are poor you will become poorer.
In case of fiat currency, they are inflationary because they are ruled by government and all the governments want the value of its money to decrease because it means country debts value will decrease and will be easier to repay.
