Bitcoin has become a currency, and we have used bitcoin for several years, but it hasn't actually been used like a fiat currency that people know. The reason is that it hasn't been supported everywhere as a payment method either online or offline. That's why people still consider Bitcoin primarily as an asset, they trade and hold it to make big profits, and more results.
That and the high volatility, preventing anyone from accepting it unless they also want to get into the currency trading business in some form, almost.