Iran is still rich in natural resources(one of the world's largest oil and gas reserves,believe they are in the top 5) many mines, oil, tourist places, a fertile soil and talented youths with a very skilled and educated youthful population and from what I have seen here in Britain and other European countries I have been to Iranians are less religious and more liberal in their thinking(not so for their government/leaders of course, while from what I have noticed during my visit to some Arab gulf states it's the opposite .lol) than their other Muslim counterparts in the middle East/Arabs/south Asia .in short the country has everything to be a prosperous developed advanced country. Seems what is holding it back is their government policies both internal and external,corruption,nepotism, favouritism, limited social freedoms, structural economic issues(very high inflation,low productivity,wages ,dominance of state in economy,high unemployment leading to brain drain towards the West etc). Sure sanctions have played a role in this, but the country also have structural issues which has contributed alot to impending Iran growth.
Seems the people's livelihood hasn't changed much unfortunately,w which given the country's huge natural resources shouldn't have been the case.