Reading makes mouths tired (and grammar causes dizziness)!
Let’s see now, this Douay-Rheims Bible is just over 1500 pages (though there are maps and other commentaries).
http://www.catholiccompany.com/catholic-books/1001875/Douay-Rheims-Bible-Black-Leather-Cover/?category=465
Also, let’s not forget that Protestants SHORTENED their Bible.
But the reality is that unless two books are printed on the same size paper, with identical fonts, font sizing, line spacing and margins, the “length” of the book is meaningless. And as has been noted, it doesn’t matter in the first place, a book is as long as it needs to be and, as is the case with the Catechism, footnotes eat up a lot of space.