The median is apparently something like "4 or 5 books" a year.

A YEAR.

In a virtue-signalling survey that will illicit higher responses than we might otherwise expect (self reported rates of untested things seen as "good" tend to be over-report on such surveys, while rates of things seen as "bad" then to be under-reported), i think that actually supports the authors point.

Especially when he/she mentions people with a stack of books on their bedstand or whom pack their kindles with multiple books at a time for holidaying.