Given the extreme value of the protections of modern copyright, should there not be more methods to prove it? If there was a public key registry to allow crypto

Given the extreme value of the protections of modern copyright, should there not be more methods to prove it? If there was a public key registry to allow cryptographically verifiable creation dates that contain detailed metadata, why, as an artist interest in preserving and protecting rights to my art, wouldn't I? Wasting that on AI is the ideological equivalent of leaving ASCAP voicemails of my farts.