Someone asked: What are the benefits of reading encyclopedia books?

I’m assuming that by “Encyclopedia Books” you mean simply hardcover encyclopedias, so my answer is framed with those in mind, but it might apply to the current crop of single-subject "coffee table" books as well.
Encyclopedias as collections of knowledge are not the same today as they were when I was a kid.  I’m 77 now, and as is the case with other things I knew and enjoyed then, technology has changed them. “Assembled knowledge” is no longer as much a static thing as it used to be; collections of assembled knowledge are more dynamic nowadays.
But way back then I had a set of Encyclopedia Brittanica Jr. and a two volume Webster’s Dictionary, that I used for homework assignments. Perhaps some would say that I was too easily distracted, but whenever I looked up a word in the dictionary, I would also read every other word on both facing pages, and when I looked up an entry in the encyclopedia, I would read the items on both sides of that as well. Homework took longer back then, and it often didn’t get done at all. The fact that I was learning other things was lost on my teachers …
Anyway, I got to enjoy those side ventures so much that I decided to start at the beginning of both the dictionary and the encyclopedia and read them from cover to cover. And I did just that, when I was 13. No, I didn't really understand all of what I was reading, but it was an interesting exposure just the same, and many times those items came back to me later – sort of like sorting through jigsaw puzzle pieces, and remembering later that a certain needed piece was "over there in that pile."
Oh, I still explored our 67 acres like any kid my age, and I ran through the woods with Hawkeye and his friends, but now I knew that the willow twig that Chingachgook gave me to chew on to relieve my headache was effective because the willow is a member of the salicaceae family, and that’s where aspirin comes from – that certain needed piece just fell into the right spot. I was interested in that information/knowledge, although I’m sure I didn’t think of it as simply that.
Was that a benefit? I think so, because even though that information was in a fixed format (which never occurred to me back then), I learned things. In those static views I could also see, and actually formulate, what I have come to call the “What Happens Next” effect. I could trace the development of an idea or invention and see where and why it had spawned some other new thing. I could see where someone invented a travois, for example, then later someone decided to put a wheel on it, making it easier to pull. That was easy to see then, but now our grandkids tend to simply jump to the Lamborghini.
Now, given almost instant encyclopedia updates, I think that too many of us today also simply discard those intermediate things, along with the ideas that helped generate them. We grab for the shiny new object, and forget the old. An analogy might be the digital vs analog watch. Those new digital things are spiffy, to be sure, with all their rockin’ new features. But I think that when we grab for the Breitling or Casio, we lose the time between the clicks that the old Bulova analog faithfully displayed for us. I think that “what happens next” happens mostly in the inbetweentime, but digital time clicks on without it.
Probably the most important item on my list of benefits is the fact that I acquired a lifelong habit of reading and learning things. I still enjoy reading encyclopedia entries. And I still use the dictionary, and still look at all the entries on both facing pages. Actually it just occurred to me that I could call them entrèes, because of all the side dishes available to accompany them, and sometimes those side dishes are ever so much tastier!
I know this is probably an overlong answer, and perhaps this was not the type of encyclopedia you had in mind, but life just is not that simple any more, and we miss so much by going the simple route, that I just refuse to do that any longer.
Now, eat your broccoli!