This doesn't surprise us in the slightest

It would surprise us immensely if the incentives had worked the other way:

While boys have long trailed behind girls in their reading aptitude, the gender gap is closing at last because they prefer reading on a screen to reading the pages of a book.

Since the Pisa education rankings in maths, science and literacy began nearly 20 years ago, girls have done better than boys at reading in every country in which the exams have been held.

Next month, however, the rankings, based on tests taken by teenagers in 80 countries, are expected to show how boys are finally catching up, according to Andreas Schleicher, the man known as “Mr Pisa” because he set up the rankings.

“Boys are doing better in the digital world. Books put off boys. But reading online changes that. There is greater digital learning by boys. They do not like books [as much] as screens,” he said.

We’d perhaps differ on the reason why but the effect we think is obvious. The existence of social media, all that stuff available on screens, makes literacy more valuable. Humans do more of things which are more valuable - therefore literacy rises as the value of being literate does.

As one of us explained it some time ago:

Economics works – social media makes basic literacy more valuable so more people will have it.

How could it be any other way?