Shower thought. If nations/states/governments are accumulating Bitcoin, then

people around the world wont use it under a pretense of a 'new world order single coin'.

think of governments making their national currencies more digital

as for the shitcoin thing
yes to americans the Euro is a shit coin.. and yes europeans will think the dollar is a shitcoin. but if a government implements their own currency. then its citizens within each nation will use that currency of that nation because.. its the legislation/law.

bitcoin is only good because it has uses. yep if people couldnt buy pizza, alpaca socks, cupcakes and ofcourse silkroad stuff early on. bitcoin would not be the same fame it is today
trying to detach that purpose from bitcoin will ruin bitcoins desire.(although i know you dont care and just want another network taking the fame)

a government cryptocurrency wont be for the benefit of letting citizens mine it for profit.
history of currencies purpose is not for profit of making the banknote/token. its for what the banknote is useful for. and the same applies today.
anyone can make a currency. but unless you can actually buy things with it. its useless
(again you purposefully dont want bitcoiners to remain using bitcoin as a daily currency. (facepalm))

anyway
what a government cryptocurrency would most likely be, is different government departments with just one custom asic in each department with just a daily electric cost of $50 but mining millions a day.
distributed in different departments to avoid a single actor(government worker) from hacking it
secured by hashes that are only accepted by government departments. thus no random '51% attack' vector
by any single government worker or hacker

anyway
government sanctions dont care what currency a country uses. they just care about penalising a country. whether that be through a fine. or even forcing a country to prohibit movement, or stop producing or exporting certain goods.
sanctions can be in many forms such as being forced to buy another countries produce or pretented from buying that same produce from another country.

EG russia stop buying european cheese and buy american instead
EG stop making missiles and make space shuttles to taxi americans to the international space station
so even if a country did adopt a crypto currency. they will still be sanctioned.

..
but back to the point
i think you are mixing up a country wanting to make its own crypto. with the stupidity of thinking a country wants to take over bitcoin..

treat it as 2 separate conversations. and realise bitcoins only real risk is idiots trying to make bitcoin less useful by trying to sway merchant to use other networks instead