within the country, you'd be committing a crime acquiring stuff using crypto. The cards are international but you're committing the act locally.
>use p2p local crypto exchanges: localcrypto, localmonero (in some countries this can be 100% anonymous by using the "withdraw from atm with 1 time code" bank services)
Will all be banned and illegal services. If it touches a bank you'll likely get extra charges on top for money laundering or similar.
>Exchange to alternate "tokens" that are legal
That will be tracked by the government if legal, or illegal if not tracked.
>Exchange locally via sneakernet
"exchange on black market"
None of these things are solutions.
There are plenty of things in ubiquitous use that are illegal in some places, or even most places. Alcohol is ubiquitous, guns are everywhere, gambling, cocaine and marijuana come to mind, people modify their cars beyond legality quite often. Lots of people do illegal financial activity as well, most people transact under the table when the opportunity arises. You can have a scenario where cryptocurrencies are widely used even in places that ban them but are so ubiquitous that enforcement is untenable.
- buy international prepaid cards for legal dervices (bitrefill)
- use p2p local crypto exchanges: localcrypto, localmonero (in some countries this can be 100% anonymous by using the "withdraw from atm with 1 time code" bank services)
- Exchange to alternate "tokens" that are legal (anyone remembers Linden dollars to BTC market around 2010?)
- Exchange locally via sneakernet.