That's interesting, but what drives the value of a coin is the people using it, and the value of Bitcoin will depend on many factors that for sure do not guarantee its future value.
States can issue a coin that takes advantage of the decentralization (to some or big extend), and borderless. They can have multiple locations running the mining rigs that run and provide the descentralized secuirity across the states, and will allow them to move funds easily from one jurisdiction to another.
Thinking that Bitcoin is bulletproof is very naive. It's current technological hedge can be challenged by many technologies and players, and if something is clear from previous experiences is that technology tends to be rendered obsolete even if had great advantages at some point . (ie from Betamax, to horse transport, four engine planes, electronic valves, etc).
so how to you stabilise price when that value is being decided globally by potentially billions of people? It's actually going to be better for Bitcoin (and the others) long term if we don't all have our eggs in the one basket. A currency that can be so different one day to the next is useless for daily spending.