The actual purpose of bitcoin was to make an alternative way for people  to trade and  exchange money on the internet , a safer way to shop online without having to use your credit card that is linked to your bank account which will compromise it,but from that idea it created the best way for hackers and bad people to use money without being tracked down, that is why governments can't control it and that is why they made it illegal in some areas, that is why it didn't become an international currency