There are two main details that support this opinion. First, digital currencies have a fixed supply. This means that it is a scarce asset, unlike traditional currency which continues to be printed. This scarcity gives it increasing value while traditional currency depreciates in value over time as more gets printed. The second detail is decentralization. Digital currency runs completely decentralized meaning that the only person that is able to use that money is the owner and no one else. Unlike banks which control all of their client's money at all times.
The main idea of this excerpt is the fact that the Grimm Brothers had a strong belief (that the most natural and pure forms of culture were linguistic and based in history) and in following it, they <em>saved</em> the fairy tale. In order to do so, the author gives a supporting detail and reveals the main idea, followed by more details.
