Already this might have discussed. The growth of bitcoin as well other digital currencies keeps progressing with time. By the time common people too have begun to use cryptocurrencies on their daily life. Compared to the fiat usage, common people using cryptocurrencies were low. When the usage increases what will be the preference of common people. Whether it gets used as investment, gambling asset, trading asset, alternate payment, darkweb usage source.
Even though bitcoin has the potential to go in any direction mentioned here and beyond. But predominantly it will be used as an investment because there is very less chance of finding a bitcoin merchant due to its price fluctuations.
Retails merchants are very sensitive to price movements because of the low margins in daily products. But 10-15% fluctuation in bitcoin price is very common which I believe is the main roadblock for cryptos to become a mainstream currency.
That's also the main reason why people prefers it as an investment.