Bitcoin was not created to discredit fiat, it was created to add value to the monetary system so it means that Fiat is still important for day to day transactions because it is easily accepted as a legal tender. The emergence of Bitcoin has become an eye opener for many people that fiat is not reliable to keep for the long term, traditional currencies are centralized and governments through their central banks can decide to print as much as they want which will eventually devalue their currency. Bitcoin is decentralized and have limited supply which means that it cannot be manipulated by any government, if you hold Bitcoin it's value will always be increasing on the long term which is profitable.