I'd like to start giving people the option of commenting on shorter Cold Takes pieces (which I don't cross-post here or provide audio for). I'm going to use this post for that: I will generally leave a comment for each piece, and people can leave their comments as replies to that.
I think the key to understanding the changes is to have a spreadsheet based on human developmental cycles. Human attraction to literally fiction is important in the periods from ages 4-25, it how we learn to read and enjoy reading in an intellectually imaginative way. Having said that, over 45, there is a collapse of productivity in reading fiction, that does not occur in those reading scientific literature, technological news, and political news. Beginning at the age of 65, those who continue to read scientific literature and technology news stay significantly current, but those who focus on political news experience a similar intellectual collapse, CNN/FOX-NEWSISM.
It is a process that is about the neuronal development, growth, plateau, and inevitable decline. As intelligent people live longer, they must transition their intellectual diet. It's why normal productive fifty year olds that have high incomes, big homes, etc, etc, don't seem to attend rock concerts, even though, thirty years earlier, they had a poster of that rock group on the wall in their dorm room.