Actually every currency in our days dont have real value. It all based by trust and reputation
I would argue that a product can have value by virtue of it's cost of production, this is the
cost-of-production theory of value. Bitcoin is not just minted at a bank, rather it is mined through work done.
It is also built on the blockchain technology, which gives it other desirable features like, immutability, trustless transactions, anonymity, decentralization which gives the currency value.