The bitcoin shouldn't be used as a a classic currency anyway, do you buy your bread or your coffee with gold?
Moreover that's true that the volatility of the cryptocurrency makes it actually unsuitable to be a real currency that your shops could accept.
In some country like japan, we can using bitcoin as payment in restaurant. But i prefer using fiat money for payment because its more practice and bitcoin is too valuable if we are using for payment
Yes, some countries can regulate crypto currency well like in Japan, but in other country they are not fully accepting crypto currency as their currency because of its volatile price, they need a permanent value the one currency that can maintain a specific value, I think the only use of crypto currency for them is an alternative source of income.