No, as always, you understand completely wrong. You know, my keys my coins!
I can deny you at any time to force me to exchange my BTC for ETH!
The US and the EU can deny Russia's central bank to use of their currencies because they don't want to let go of their money for garbage!
On the other hand, the CB of Russia is telling their people to not try to buy USD or EUR because they are not allowed, despite those rubles being their own money!
Think who has the keys in this analogy and understand who the one telling others they are not allowed to use their own money as they wish is here! Besides, this is not the USSR, you can't simply fake everything that happens in that country, I know even guys in telegram channels dedicated to mining are talking about how to get USD on the black market, or use yuans to swap it, so the fiat is there, is just that the government doesn't want you to get it.
For a guy who comes from a country that banned even this forum, I'm certainly amazed that you can't understand basic things while you still keep coming here daily, well, less for actually discussing bitcoin and more for Russian propaganda but I do somehow understand the desperation in some, I've seen it numerous times in the last 4 decades.