Adding to a public ledger needs some mechanism to deter people from junking up the system for everyone. In Bitcoin/other crypto, that's mostly represented as a flat "gas" fee that is added on top of your transaction. This is also easy to control because the only thing Bitcoin is storing is account balances. For pretty much everything that isn't solely relegated to storing numbers, moderation becomes an immediate issue since everything is immutable.

So, yeah, I think it is all about cryptocurrency. Trying to build anything other than a public bean-counter would probably prove insurmountable.