I think the game is bugged. When I read “helpful” books, I get the pips, but it doesn’t make the final book any more likely to appear, only catalogs do (played on Hard). It came to a ridiculous point where my top was full of pips, yet no book in sight (also I believe these may increase difficulty of levels as well? Like more librarians).
It works as intended. Both helpful books and catalogues bring you closer to the final book, but to actually find it, you still need to make the final step in the right direction according to a catalogue. If you are already as close to the final book as it can be, reading another helpful book won't make it appear in the current room - you need to follow the direction provided by the catalogue to find the book in the next room.
I tried to get to the final room by reading only Helpful books and it wasn’t possible, no matter how many pips you got (you do get more and more ghosts). I think past a certain threshold any future room should get the needed book… I don’t mean the room you are already in, but the book never appears without the catalogues, which is confusing.