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.
The world discredit can be subjective. If you go back to Bitcoin timeline when the Bitcoin Genesis block was live. The included "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks”, the banks were literally in Chaos begging the government for help because without them, the system will be done for long. What were they doing that time? The government was printing money and this didn't happened once, this happened twice because the system is a total failure.
Bitcoin maximum supply is capped, there is no way more Bitcoin will be coming from any angle, we don't have any bailout from anywhere and I'm not even sure if government are the people we are going to be calling for help if we need any help. Bitcoin has collapsed multiple times in the several times in the last 15 years and it's standing strong like never before and you really think Fiat system is superior or can stand where Bitcoin stand? They are not even close to each other but share some values.