And bitcoin ban is even less enforceable, equivalent to banning math – good luck with that.
Not really. Why should it? Making it illegal would make it illegal for any national company to accept bitcoin for paiment. And no exchanges could be maintained in the country. But yeah. Holding and exchanging bitcoin might not be possible.
It'll create friction for exchange use for sure, but if you're holding in cold storage you can just either wait it out or leave the country. And keeping 12-24 words hidden is easier than a gold.
Yes this for sure is possible. But temporally it can lower the price of cryptocurrencies, when some marketplaces stop working.