I wonder, would those people be able to do those things if the information were presented by spoken word? I suspect (and could be way wrong, of course) that this is more about ability to understand stuff in general, and not really related to being able to read and write.
We still have that, in 1st world countries. (I've used the wikipedia entry for the US, but rates are similar across EU)
https://en.wikipedia.org/wiki/Literacy_in_the_United_States
> This government study showed that 21% to 23% of adult Americans were not "able to locate information in text", could not "make low-level inferences using printed materials", and were unable to "integrate easily identifiable pieces of information."