Your original claim was that fiat currencies had intrinsic value. I don't see how 1) or 2) support the fact a fiat currency has intrinsic value. On the contrary, history shows that fiat currencies always significantly lose value over time. The USD for example has lost 85% of its value over the last 50 years. How is this observation compatible with any sort of intrinsic value? "Guns" and "taxes" did nothing to prevent this loss of value...
What you are trying to say, I believe, is that fiat currencies will likely have some value in the future because they are in demand (notably from taxes). That is true, but this is no different from Bitcoin: it has value because it is in demand. I would argue that the potential demand for Bitcoin is higher than the potential demand for USD, if only because there are billion of people across the world from countries with terrible fiscal policies for whom Bitcoin is clearly superior to their local inflation-ridden currencies. Compare this number to the merely 200 million tax payers in the USA.
What you are trying to say, I believe, is that fiat currencies will likely have some value in the future because they are in demand (notably from taxes). That is true, but this is no different from Bitcoin: it has value because it is in demand. I would argue that the potential demand for Bitcoin is higher than the potential demand for USD, if only because there are billion of people across the world from countries with terrible fiscal policies for whom Bitcoin is clearly superior to their local inflation-ridden currencies. Compare this number to the merely 200 million tax payers in the USA.