Naive? Where did I say it'd be easy? I said that's the only way. These technical workarounds only prop up and help the bad government, which crypto fans vehemently ignore.
Most will have offshore accounts hidden in various shady or neutral jurisdictions that will ensure they live out the rest of their days without issue (see Zimbabwe, Nazi Germany, or recently Sri Lanka). They could even wipe out large swathes of their population completely and it would still do nothing to destabilise the government (again, see Soviet Union, Nazi Germany, Khmer Rouge, the list goes on)
I can tell you real people there aren't buying bread and milk with it.
But anyway, the same mechanism you imagine being used for buying bread and milk can be and probably is used to buy war drones.
Actually it's much easier to give cash in exchange for bread and milk than bother with crypto but it's much more difficult to get a large amount of cash from Russia to Iran intact than to send them some crypto