I would really like to blame how busy I am (new startup, 3 kids, other commitments), however I see my wife who is a physician who works in 2 departments and also teaches and runs a residency program and I know she is quantitatively much busier than I am and has far less control over her time.
However, she manages to read a couple of books a month at least.
I think that during the 2000s/2010s when I was sucking in a firehose of information and learning to consume exclusively in places like HN, she was still researching, studying and learning through long form papers, textbooks and experiments. Our brains are trained on very different cadences.
So when she sits down to read, there is almost no distraction, her comprehension is far better than mine, and she sort of shoots through a chapter with much better momentum than me.
I've recently resolved to stop trying to read anything popular/trendy that I might be attracted to just because it's there and instead only read history, which is my real interest. No more business books or novels I don't really enjoy. That has made a difference and it's already becoming much easier as I am more disciplined about it.