Russia's desperately terrible internal financials, applied to any nation lacking strategic deterrence, would have brought them a lot more pain.
I sort of jokingly contend that they're floated by a theoretical "Blood Standard", in addition to the very distributed basket of commodities they built their country on top of.
The problem here is that I've got the mechanism reversed. Blood Standard measures negative power - the capacity to destroy. Reserve status tracks positive power - the ability to keep other states from destruction. So maybe what the Blood Standard really represents is super-sovereignty - you never get under the thumb of IMF, you never get invaded, you don't lose control of internal monetary policy a la Argentina.
Thinking about it, the Swiss break this model, but from the other direction. "We will never ever screw with you" and in return they get seen as safe.
Again it's a bit of a lark, but it's not as funny anymore, as the growth curve in positive economics hits some natural physical limits along with a very deep gravity well.