I don't think this shows that the author is incorrect. As far as I can tell, the author is arguing that it does not make sense to wring our hands over the death

I don't think this shows that the author is incorrect. As far as I can tell, the author is arguing that it does not make sense to wring our hands over the death or life of "deep reading" because it has always been an unpopular activity. Books were only genuinely popular when people had no other form of passive entertainment, but even then people were just reading the way most people watch TV now, as a way to pass time. The fact that most people say they read at least one book tells us pretty much nothing about the state of deep reading, and therefore is not very relevant to the linked article. Granted, the linked article doesn't cite sources for its conclusions either, but based on the books I see read in public...I believe them.