The article says "That’s by design: bitcoins were created to be the most fungible commodity the world had ever seen". Could someone please share a citation for

The article says "That’s by design: bitcoins were created to be the most fungible commodity the world had ever seen". Could someone please share a citation for that? I understand that both currencies and commodities are undifferentiated and so are more easily traded, so I can see similarities. But, from a common usage perspective, as well as from an economic viewpoint, a commodity is defined as a good, having value in itself. So the above claim seems rather misguided. Am I missing something?