I grew up using Wordwise Plus on the BBC Model B, where what you saw on screen made no attempt to replicate what it might look like when printed (in fact, all text editing was done in a 40-column mode to save memory). You were forced to think about the textual content, and not about the layout.
Then someone invented the "WYSIWYG" concept -- and from that moment on, word processing went completely and irreversibly tits-up, as people began to pay more attention to appearance than content. (The final triumph of style over substance came with WordPad, which eschewed sensible-but-mundane stuff such as a spelling checker in favour of the ability to use multiple fonts and text effects. Oh, and NotePad lost the ability -- which DOS EDIT always used to have -- to import unix / Amiga text files with LF line-endings.)
In my last job, I once was tasked with editing a Word document created by someone who evidently didn't understand the difference between a word processor and a fancy typewriter. The whole mess had been laid out using spaces for formatting, randomly-applied bold/underlining/fonts -- and the table of contents was typed by hand. I kid you not, even the header on each page had been typed manually -- and the right-justification on odd-numbered pages done with spaces.
My task was to insert one word into a paragraph. Unfortunately, that extra word caused it to overflow and, as a result, bollocks up the pagination of the *entire* document. I searched for somewhere, anywhere I could perhaps delete a line to compensate, but to no avail. It took me two days to replace all the crude space-formatting and create a *proper* table of contents (which would have survived any future insertions and deletions). All I got to show for it was a ticking-off for taking too long to "just quickly insert one word".