Fiat is designed to lose value, 2 percent in some countries, 2 1/2 in others. Bitcoin not.
Bitcoin too, until the year 2150 or something ! Although you are right that bitcoin has monetary mass inflation until then, while many central banks have price inflation targets. The difference between both is (at constant velocity) given by economic growth.
The danger is altcoins. Altcoins = infinite inflation potential for crypto-currencies as a class. Though so far they aren't catching on.