Earlier quoted context omitted.
Between the years 150 and 100 BC, the Seleucid tetradrachm went from 95% silver to 65%. As the name suggests, it continued to weigh four drachms. Debasement occurs any time the government runs out of money and can force people to take the debased money. The previous ~150 years of the same government minted tetradrachms that were all silver, probably because their main use of the silver was paying foreign mercenaries.…
> This isn't plausible Why? Of course it wasn't accessible or particularly useful for the majority of people but it was central to the Byzantine economy/financial-system functioned. Soldiers were paid in gold (every 6 or 12 months so that simplified things) and taxes were also collected in gold whenever feasible. Relying on gold as your primary currnecy of course wasn't ideal since the outcome was a partially demonet…
Well, for one thing, most people wouldn't be able to afford a single gold coin. You might collect taxes from a province in gold; you're not going to collect taxes from a person that way.
> the outcome was a partially demonetisation of the wider economy
This is also an odd claim; the number of denarii kept going up.
> it was central to [the way] the Byzantine economy/financial-system functioned.
Any time you have a system that doesn't involve something, that thing that isn't involved also isn't central to the functioning of the system. There is no way for such a rare coin to be central to the functioning of the system - if it disappeared entirely, the system would continue exactly as before, since almost nothing would have changed.