Gold can't be used as a currency but it still holds value. I don't think the two are mutually exclusive. Bitcoin is the first ever digitally scarce entity. I think its easy to imagine a new generation used to technology placing value on this. As for it being a currency well once the volatility stop why not
Yes, gold is a kind of treasure, it has value because people are amaze when they see the sparkling brought by it. Like bitcoin it also have that kind of treasury thing because when you hold it for long term it could be sold at high value when time comes. And some company is now producing a bitcoin model coin so that it can be treasured.