You truelly do not understand how economies work do you?
Cuba and North Korea are under an embargoo, meaning the US and its vassals who have no own real government which are just puppets of Pentagon, imposse embargoos on Cuba,North Korea,Iran and other countries.
So this countries can not buy materials (resources) which they do not have on their own soil, like precious metals, oil for plastic procedurment. All this lack of resources means they can not establish facilities to produce goods which they can export, so they have to relly on what they actually have in their own small countries.
We could cripple the UK within one single year back to such a primitive state if we empose embargoos from all major countries and exporteurs of valueable resources. UK has not own resources except of view oil sources on sea, but if we cut everything that is produced in another country and not on international waters than UK would cripple down to substandards of same level as North Korea.
In case of iran, they have build facilities to be more autonomous than cuba and north korea, so embargoos only raise the costs of the goods but do not cut the supply off entirely. It is hard for normal people who do not earn a lot but the state is providing every iranian family with subsidy of the oil they export and subsidy for living and monthly subsidy for gas, free housing and education. But sure, it is the capitalism that ensures "living standards".
Socialistic methods are implemented in western countries but you overlook them.
The true polish spirit poking everyone they are related to, but selling themselfs off to people they have zero cultural nor historical roots.