From a practical point of view, when looking to the past ( nothing new under the sun) two examples stand out: Templar banking system and the Amsterdam Exchange bank. Or the Haladawar may serve as an example too.

In both cases it was a simple straight forward process. You would simply go to such a banker, Depot your assets and you would receive a written note or notes in a certain weight of gold/ silver, and go about your business. It is basically a cashier system.

True, it is somewhat centralized as the cashier function is done by one in 100.000 or so.

On the other hand there really is nothing to preclude anyone from creating their own currency. Assayers and auditors are functions of all ages. There are ways to enhance trust.

What I notice is the push for trustless. I think philosophically, and morally, it is a degrading issue. It is the man of his word that breeds success.

For a parallel functioning economy trust is essential. Gold/silver and crypto, especially the anonymous kind are made to be paired.

However, the biggest threat to such a system is the current system. By price manipulation they could out-spent anyone.

So, this fiat currency counter fitting system must end, and that right needs to be taken away from them.

Personally, I choose to get paid in silver/gold and it is really nice to do so. The people I speak to are amazed such a thing can be done. It is not going very fast in terms of growth, but the response I see is people feel better being paid in value than being paid in something arbitrary.

Crossover is still not feasible, cause we need decentralized energy production. ( Working on it) once that happens, ...