One of the phenomenal stories that proves that Bitcoin / Cryptocurrency CANNOT or is not suitable to be used as a currency for a medium of exchange or payment is the story of someone who once bought a baking dish with a Bitcoin of 10000 BTC. If only that person, using 10000 BTC at the moment, is not just the Pizza he will get, the Pizza company is all he can buy.
So? Still thinking about Bitcoin as money? Still like to promote Bitcoin as an alternative currency and drive other people to buy this using Bitcoin?
So? The value of fiat changes every day as well but the variations in the value of fiat are slower that is why you do not notice it as much, but while the value of bitcoin over the long term only goes up the value of fiat over the long term has gone down, fiat has lost more than 98% of its value in the last 100 years while the value of bitcoin in the last 10 years has grown almost infinitely, to me it is very obvious which currency I prefer.