Bitcoin fails to satisfactorily answer von Mises' regression theorem.
Nope
It also has no scarcity since it can face competition by an infinite number of similar
This is syntactically identical to the following argument; Gold has no scarcity because it can face competition from an infinite number of other physical materials.
once it is perceived as more than just a nuisance by some major government it will be shut down in a heartbeat.
This is syntactically identical to the following argument; Once asteroids are perceived as more than just a nuisance by dinosaurs, they will erect an asteroid defense system in a heartbeat.
Future generations will laugh at our incredulity just like we make fun of the Tulip mania (which had more substance to boot).
Because you don't understand the above, it's perfectly reasonable that you would think this.
But given that such a currency will antagonize major governments
This needs to be re-stated because you seem convinced with quite some certainty about the relevance of this. Bitcoin specifically, and modern peer to peer distributed cryptocurrencies in general, were constructed with the understanding that the infrastructure that they consist of would be an existential threat to the state, and the state may well respond accordingly.
Armies employing firearms are similarly unphased by the idea that they may attract the opprobrium of armoured heavy cavalry due to their unsportsmanlike conduct and the fact that the latter precipitates the obsolescence of the former, but they were designed with that understanding in mind. The very fact that you acknowledge there is insatiable global demand for a currency should be a good indicator to you that this is just a decisive blow in an extremely long war, not as you assume, a relic of the political naivety of the designers of, and the community stewarding, Bitcoin and other peer to peer distributed cryptocurrencies.
Dinosaurs were killed by asteroids because they had no model for understanding the threat with which they were faced, and no mechanism for defense against such a threat even if they did so understand it.
Heavy cavalry was obsoleted by modern firearms regardless of their understanding, because when you charge a fortified cheap and low maintenance machine gun emplacement with your expensive and high maintenance heavy cavalry, it will be annihilated.
The state will be obsoleted by distributed peer to peer cryptocurrencies, because regardless of their understanding, they are unable to enforce a mechanism to prohibit the performance of the mathematical equations constituting the necessary cryptography backing these peer to peer cryptocurrencies, and this exsanguinates their economic parasitism, subjecting them to the full force of free market competition as a consequence, and thus their annihilation, because everyone well knows that they cannot compete in such circumstances, and have only endured until this point by violent coercion masquerading as benevolent social stewardship.
it will likely not be a crypto-currency but rather a currency backed by some sufficiently powerful country.
There is simply no need for such a beast when a purely free market invulnerable infrastructure for the transmission of value between anonymous actors in a trustworthy fashion already exists.
am actually expecting the Russians or Chinese to launch a 100% gold-backed currency within the next 5 years
Which would actually be a final surrender, as a gold backed currency is once again something that they are unable to infinitely parasite from through central bank manipulation. I agree with your analysis on this front and see it as a positive thing. It has no bearing on the success of cryptocurrencies, nor the nature of them dealing a killer blow to any fiat currency which a state would otherwise be able to infinitely parasite from by manipulation.
A world in which gold backed currencies exist alongside cryptocurrencies is perfectly reasonable.
Failing that, when the EU breaks up the new Deutsche mark will be a good alternative
Unless it's backed by a suitable commodity, it's not going to win, for all of the aforementioned reasons, and if it is backed by a suitable commodity, it's not a problem for cryptocurrencies.