Some of us figured out that mankind ceased to use shells and beads (and many other things much more fixed in supply than Bitcoin) aeons ago because few people were required to settle their debts or taxes in them, and therefore their future value was entirely dependent on volatile collector sentiment rather than a broad segment of society needing them. I wonder when Bitcoiners will catch up...
> Why did the people/government choose to make bank notes legal tender, when they already had gold as legal tender
The notes came into play because of demand for credit, and the monopolist of legal force in the territory preferred to legislate legal tender as something they had control over and earned seigniorage from, which was incidentally also easier to maintain a balance of supply and demand in (if they were minded to do so).
What states absolutely aren't looking to denominate debt in is a volatile synthetic asset whose limited supply is mostly in the hands of shady, unproductive foreigners, which was created out of explicit hostility to credit markets but is now propped up entirely by a speculative asset bubble.
Now that you understand that, you can finally catch up with non-Bitcoiners!