Digital artwork always reduces to an integer, what's the point of buying a number? If you want to give money to the creator, just give money to the creator. Not sure I understand the value of adding a rube goldberg machine to the mix.
The way I understand the appeal is that there is a notion of (virtual) authenticity. It is like paying for the signature. Imagine you own a copy of a painting by Van Gogh, or a painting which cannot be authenticated, then it is suddenly worth a lot less than a painting with a certificate that it is an authentic one and another certificate that you obtained it through legal means.