Indeed that is a variable I've thought about... but whether USD loses 2% value in a year or 10%, that number is pretty small compared to consistent 100% relative gains every year against USD. I think the doubling-curve metric will only break under blatant hyperinflation.
In addition, while the value of the dollar may be declining, the value of other products and services is also declining due to abundance technology. This creates a scenario were prices aren't changing for certain things.
Also as the demand for certain old-school products drops (crude oil) this also lowers the value in tandem with the dollar.
And lastly, no one argued with me on this doubling curve issue until Bitcoin spiked above it three months ago. Now everyone wants to think that we've somehow set a new standard... I doubt it.
You know what they say... the market can stay irrational longer than your model can stay intact 😂