[munificent]

> pages don't get added dynamically when adding new content as easily as they do in a typesetting application.

InDesign will actually do this. I think it's called "Dynamic Flow" or something? It can automatically append new pages to fit the content.

In general, it's not very eager to do this because when you consider spreads (distinct left-hand and right-hand pages), inserting a new page will affect the layout of all subsequent pages. You could insert a new spread, but that may not be what the user wants.

In other words, if the user is laying out pages, actual pages matter. They aren't just an implementation detail derived from the length of the text.