Bitcoin is already a currency but it is not yet really used like the fiat currencies. The reason is that it is not yet supported everywhere as a payment method either online or offline. That is why people still considering Bitcoin mainly as an asset, they trade and hold it for making good profits.
Most of the countries now are legalized the use of bitcoin and I guess they already recognize it as currency where they exchange it in different product. The reason why they keep on using it as an asset because of income that they could get. But, I think bitcoin can really use as currency and asset at the same time.