> Is there value in identifying the difference between reading a longer article like this one and an actual book?

Almost every study that looks at this finds that there is. Between the time for deeper contemplation, cognitive load of sustained attention and greater potential information content of a larger body of text compared with a smaller one, someone who reads books is generally going to more competently understand things gestures generally than someone who gets everything from articles online.

I think the major difference is that this article describes some meta concept. Despite being abstract its very concrete. If 2 people read something that is fantasy or even describing a physical process like wood carving. Despite reading the same thing both parties have an entirely different picture of what happened. The clothes on the people are different, the building they occupy is different, the wood you are carving is different, the tools you use are different. These difference are actually the most increasing details which your brain fills in, and this is something completely different from when you watch TV. All the details are filled its concrete and non-abstract. It can still be a compeling story or piece of art but often people are are much worst artist and visual things rarely capture all the things your brain can fill in for detail that make something cohesive. And the details they fill in are often details your brain finds mundane and ignores entirely.

I've been learning about wood turning and carving recent and the amount of character it instils in what use to be dead piece of furniture in a room is honestly life changing. Reading can do this but there are other physical activities which I think a digital society loses touch with. Most of the Ikea furniture today is well engineering but artistically dead (definitely cheaper though :D ).

I’m not familiar with the research but I will say that conclusion “feels” right to me.

Have they found a modern day metric that we should all be hunting in our quest for reading health? A literary equivalent to the daily 10,000 steps?

Maybe 10,000 words!

How could less correlated reading, no matter how high the quality, possibly compare to a solid book - in use of time or depth of impact?

The second chapter of every book has the advantage of being written, taking for granted that the previous chapter was read. The density and complexity writers and readers can handle in each chapter, keeps increasing throughout a book.

Short reads can convey important things, but nowhere near as many per page.

If you took any wonderful dense book about anything important, and turned it into short reads, with lower correlations of who finds them, reads them, and when, the page count would have to increase 10x - 100x. The setups and redundancy would be immense.

Books also get to explore many perspectives on the same important ideas. Which is not redundancy. It is the difference between recognizing a good idea and understanding it.

Feeling an epiphany vs. absorbing its implications. Awareness vs. fluency.