One can keep writing forever, but I think... If you can't capture it in 314 pages, you might be writing less of a universal book than intended.
So it’s entirely possible that at some point the author ends up capturing what they wanted to capture and the total number of pages then is lower than they are today even.
I dont find this book to be universal, this topic is so wide that maybe 30 000 pages won't be enough. Some CS books are >1500 pages look at the whole series "the art of computer programming"