Crypto is backed by other people who trade it, and its a store of value traded and valued re-veered for its mathematical basis. The cryptography itself is the basis... the value of a network spiraling off into complex proof of work hashes is the value and its a deep seated human nature that makes people want to collect something that CANNOT be duplicated. Paper fiat money got us to the point of computers and internet where the Gold is where it belongs, used as a precious commodity for hi tech manufacturing!

Also this is besides the point as unbacked paper fiat backed by No gold brought us to a point of wealth unimaginable to people using the gold standard a hundred years in the past.