What a shared digital economy needs is interoperability, not cryptocurrency: a database or a standards body does the job, exactly as railway standardisation did.

What you need is interoperability. Interoperability can happen through a blockchain, it can happen through a database, it can happen through standards bodies with defining standards and protocols. And we've been doing it for hundreds of years since the railroads were standardized. And it's not something that totally requires a novel technological solution.