But if you have even one collaborator who goes in and hammers something by applying manual formatting, the whole thing can be ruined. Actual images can end up showing up along with its caption in the Table of Figures. Entries can go missing from tables. Lone paragraphs can randomly end up with a different style.
Word can successfully manage large, complex documents, but it requires discipline. (as does LaTeX)
I would submit that the same is true for LaTeX.
I've done plenty of work where the customer insists that the final deliverable be in Word format, because that's what they're comfortable with. You can do proper formatting in Word once you learn the tools, and it's not even all that hard, although it can be somewhat unforgiving of screwups. The one thing I wouldn't attempt is to convert a TeX document to Word. In theory that shouldn't be entirely possible, but in practice there are about a million ways it could blow up in your face.
And I've yet to find a guide which instructs on how to set it up properly, how to share styles across documents etc. Do you know of one?
20 years of writing HTML and CSS has spoiled me; many times I'm using Word and thinking "I could do this with one rule in CSS" (often some crazy positioning nonsense with images/tables). If only!
When my wife wrote her doctorate she did none of those things, and I ended up spending the best part of two days laboriously going through the entire document to make it conform to the university's style guide for thesis being submitted. Thankfully she uses Scrivener for writing now which as near as possible enforces doing things the right way the first time.