The Romans were only able to fund the expansion of the empire by overextending their resources. This meant that the empire became too expensive to maintain without relying on tactics like currency debasement, subsequently triggering many of the other symptoms of decline that you listed.
Of course, we aren't living in the Roman Empire today. But what is consistent is that delegating monetary policy to a third party means that they can overspend and inflate the currency base, charitably for reasons of national interest, cynically for their own gain.
The rise of cryptocurrencies like Bitcoin is a sign that many people want to reduce their personal exposure to this.
> The Romans were only able to fund the expansion of the empire by overextending their resources.
No, they never ran out of the resources needed to expand. It just became more individually profitable to spend those resources on internal competition, and eventually civil war, than on growing the pie.
> This meant that the empire became too expensive to maintain without relying on tactics like currency debasement, subsequently triggering many of the other symptoms of decline that you listed.
Even if we take this at face value, that doesn't sound like currency debasement causing the collapse - if anything it allowed them to stave it off at least for a time. Businesses renegotiating their loans/bonds is normally a precursor to going bankrupt, but that doesn't mean renegotiating your loans/bonds causes bankruptcy; if you took your loans/bonds in a form where you can't renegotiate them, that only makes you more likely to go bankrupt sooner.
(Traditional currencies are in many ways like a slightly odd bond that doesn't pay interest)
Of course, we aren't living in the Roman Empire today. But what is consistent is that delegating monetary policy to a third party means that they can overspend and inflate the currency base, charitably for reasons of national interest, cynically for their own gain.
The rise of cryptocurrencies like Bitcoin is a sign that many people want to reduce their personal exposure to this.