It seems to me that bitcoin is now used more as an investment than as a currency, since the possibility of convenient payment with bitcoin is not yet so widespread. But as an investment, it is a very good option, and its high volatility is a good opportunity for this.
Not only now, it has never been used as a currency in the past and will never be in the future. Not because it is not popular or because the government does not allow it, but because no one wants to use it as currency. If we're being honest, and between profit and privacy, I don't think many people would choose privacy. Most people will choose profit and that will always come first, so the prospect of bitcoin being used as a common currency will never happen.
Of course, volatility is an advantage when it comes to investing because it creates more opportunities for investors.