It is the same why does the fiat currency has value because today most of the people are using the fiat currency for making transaction and by the creator of the bitcoin he wants to make it more digital currency so all of the transactions today are we can do by the help of the internet world or the cyberspace now this is the most use transaction and they are now supported the conversion of fiat currency into cryptocurrency that you can convert your money into the digital world that you can now pay a lot of things through online without using physical money it has a value because it is the same like the fiat currency today.
It is not the same, you can see that in panic, everything is dumped for fiat currency, because fiat money is considered as a standard unit of value, thus its value never changes. Although this is just an illusion ironed in everybody's mind, but it works quite well and almost everyone has become the slave of it