I've never seen a good study which indicates that literacy extended much beyond the priest class and certain upper class types, and those of their servants who needed to be literate.
In Isaiah 10:19 one of the calamities coming upon Assyria was to be reduction of their trees to such a low number a young boy could write down a description of them.
Again in Isaiah 29:12 the words of the book would be as though sealed to the prophets and to others as though they were unlearned or unable to read. Both groups could read but would be hindered from doing so.
And there is David and men like Peter who came from lowly circumstances but were more literate than a large proportion of Americans.
But in none of these case was literacy treated as unusual or as a special skill.
Even in Deut.6:8,9 Israel is commanded to write the law on their door posts and gates. True, it was likely a figurative “writing” but such a command would have little meaning to a largely illiterate population.
So “I expect that literacy in nation of Israel was more common than most of us would think”.