I've done extensive study on pre-Revolution Iran under Mohammad Reza Shah Pahlavi so I can't say much about pre-Taliban Afghanistan.
As the saying goes, a picture is worth 1000 words. One thing you have to understand the pictures we see today taken 40 or 50 years ago are mostly owned by the wealthy and the upper-middle class, or by Western journalists visiting the country. For example on the front page today, I would assume this picture was taken at Tehran University, in the capital of Iran, Tehran. The percentage of Iranians that went to universities in the 1970s was a whooping 0.43% probably less than 5% of the total population (source below).^1 This 0.43% 5% percent also included extremely wealthy Iranians who benefited from the Shah's pro-industrial policies that included oil and natural gasses, and their kids also had a chance to study at universities in Paris, the United Kingdom and/or the United States - so the percentage studying in Iran is much lower.
Mohammad Reza Shah Pahlavi, the last Shah of the Pahlavi Dynasty in Iran from 1941 to 1979, wanted the West to perceive Iran as a "civilized" and "modern" country. To explain why I left quotes around "civilized" and "modern" is because non-western countries wanted to be modernized under western standards. Back during the 18th and 19th century colonization, the only countries that were not colonized were Turkey, Iran, Ethiopia (before the 1930s), Thailand, Japan (to an extent), and many others that I can't think of right now. If you were to take a look at the pictures taken in those countries, the military generals and/or politicians were wearing western clothes in order to look "civilized" just like the West. The Shah wanted to "look western" in order to become accepted within the European sphere of influence. In many cases, these pictures were taken by the Iranian state media and handed over to western journalists to prove that Iran is westernizing and modernizing just like Europe and the U.S.
To answer your question, since a very small minority were exposed to western culture, and even less so to appear in pictures, those photos taken in Iran are very inaccurate in the portrayal of ordinary Iranians, whom the vast majority still practice Shia Islam and rejected the Shah's westernizing programs such as his 1963 White Revolution. I would even argue that the pictures we see today about "pre-Revolution Iran" are taken intentionally to give us the impression that Pahlavi Iran is "civilized" and "modernized". A picture isn't worth 1000 words, it only deserves one: propaganda.
1.1976 numbers when the first national census was taken.
Iranian population in 1976: 33,491,000.
# of people who attended secondary schools: 741,000
# of people who attended vocational schools: 227,000
# of people who attended colleges in Iran: 145,210
# of people who attended colleges abroad: 80,000
Percentage of Iranians who attended colleges in Iran: 0.04% 0.43% (Thanks /u/boris1892)
Source: Ervand Abrahamian. A History of Modern Iran. Cambridge University Press. 2016. Pg 134.
Here are some sources to consider (I will be adding more as I sift through my sources):
Kazemi, Farhad. Poverty and Revolution in Iran: The Migrant Poor, Urban Marginality, and Politics. New York: New York University Press, 1980.
Farhad Kazemi gives a historical background in the urbanization of Iran in the 20th century. He contrasts the rising urban areas versus the rural areas under Mohammad Reza Shah Pahlavi. Kazemi emphasizes the massive transformation of wealth after the 1973 oil crisis that allowed the upper class Iranians to enjoy the living standards of 1970 Europeans.
EDIT: Spelling. Formatting.
EDIT2: Included Sources.
EDIT3: Included correct population percentage of those who attended college.
I can address the Pre-Taliban, Pre-Soviet Afghanistan part of your question as I have done extensive research in that realm. Sorry, however, to be getting to this late.
Afghanistan during the Musahiban Dynasty (r. 1930-1978) was very "separated" for lack of a better term. Educated, affluent technocrats occupied the cities (which therefore became more liberal), while uneducated, often illiterate Afghans occupied most of the rural areas. These rural areas haven't changed much socially in the past 50 years, nor have they in the past 250 or so years since Afghanistan's founding. This created a social rift between two parallel societies. However, the Musahiban dynasty was exceptionally skilled at balancing the periphery against the center -- this is a phrase I use to describe how the central government made sure to let rural communities largely govern themselves as they had done for literally hundreds of years. Really, the urban areas didn't really undergo massive change until the late 80s/early 90s as the Mujahideen began to close in. For instance, in most of my research it seems that many scholars see the Hekmatyar-Masood fight over Kabul in which Hekmatyar saturated the city with rocket attacks the beginning of the end for this (relative) extreme liberalization of Kabul. In conclusion, this "estimation" you allude to is somewhat accurate - if not showing the full picture. The estimation shows a very, very narrow view of Afghan city life amongst a largely educated population.
What it does not show is the other side of the coin. The rural areas remained extremely conservative through this time - evidence in this can be seen with how quick backlash was against the Soviet invasion and the People's Democratic Party of Afghanistan. Both forces attempted to exert central government control over traditional governing structures embedded deep in rural life. This is always a recipe for disaster.
The above is not to say that the rural areas did not change between 1978 and 2017, because they absolutely did. However, the presence of an extremely conservative population is still in place, though this population is considerably more "tuned into" violence than their 1978 counterparts. However, it is important to note that as between 1978 and 1989, the modern guerrilla in rural Afghanistan is not fighting for ideological reasons in most cases, but rather exertion of government control.
Therefore, and as previously mentioned, the narrative that Soviet/Taliban/Pakistan/NATO assaults on Afghan society destroyed a "liberal society in the Middle East" is only really half true - there are much more issues at play. If the idea of a liberal society in Afghanistan were widespread and legitimate, the "jihad" message of the mujahideen and subsequently, the Taliban, would not have worked nearly as effectively.
Sources:
No Good Men Among the Living, by Anand Gopal
Afghanistan, by Thomas Barfield
An Intimate War: An Oral History of the Helmand Conflict, by Mike Martin
The Wars of Afghanistan, by Peter Tomsen