Above these to reasons, volatility is considered. For bitcoin or any other digital asset to serve the purpose of a currency, stability is required. At the moment, bitcoin is looked at as an investment by common people and they intend to improve their financial status with bitcoin. It is just a matter of time before bitcoin becomes a currency. Actually, there are places where bitcoin is used as a medium of exchange.
People have taken this opportunity as this is not controlled by the government or by someone, so this volatility made people have the opportunity to earn, they are using this to hype and to make fud so they can buy more and sell more, so the government is not ready for this digital currency to make it as an official currency, unless they can control it. But so far although it won't make as a currency, it is still considered as one form of investment.
Government is not giving bitcoin officially in some states the status of a currency but we have seen that many famous companies are using it as a mode of payment. On the large scale bitcoin is still used as an investment which will generate good money upon staying in wallet during dumps but it does not mean it is not being used as currency. I feel like within next 2, 3 years it would be official used as currency.