Up until very recently, though, there has been no such selection pressure acting in favor of the varied capacities which go to make up a proficient reader or writer. Hence proficient readers and writers remain rare. One result, it might be argued, has been to increase social inequalities, disproportionately rewarding a very unevenly distributed set of attributes. The capabilities which allow some of us to read with real ease, were apparently of little evolutionary importance until very recent times and hence are very unevenly distributed. Because we think of print as very much a low-tech medium, we do not think of ourselves, as participants in a print culture, as enslaved to the dictates of technological convenience.
Print is, or has been, the cheapest and most efficient information storage medium available.
It is not the easiest to use. Such potentialities in view, it is possible to imagine scenarios in which, a generation or so hence, no more of us will have to know how to read easily than now know how easily to read Latin. Icons and voice-overs could do the rest. Were it so, it would, I think be a blessing. For all kinds of reasons.