I'm also a big FOSS supporter, and I detest using Microsoft products for many reasons.
That said, here's a fairly hardnosed take on the subject, from Charles Stross, a very successful author and sound thinker - who is also a FOSS advocate:
MS made what seems like an intensely stupid engineering decision about visual formatting: to simultaneously support two totally separate formatting schemes. These two do NOT work together very well. This creates intense complexity within the file format. It also creates low-level logic problems that are so bad that not even Microsoft can guarantee that the visual formatting of their own files is going to be consistent in all cases.
This weakness doesn't matter much to the home and office customers that make up the huge majority of Word users. But it's a real problem for extremely format-sensitive work. Like publishing.
MS, through market manipulation, managed to force almost everyone to use Windows, Office, and Word. The publishing industry was not exempt.
Then, MS decided to double down on their awful file format by breaking backwards compatibility with each new release of their own product. Making sure that everybody had to buy a copy of the new version of Word, or else be left behind. Charlie: "Each new version of Word defaulted to writing a new format of file which could not be parsed by older copies of the program."
As the file formats changed over time, they didn't get better. From Microsoft's point of view, the bad file format was a feature, not a bug: Word, having achieved near-monopoly status, is pretty thoroughly sheltered from competition.
Why I still have to use Microsoft Word (even though I hate it)
"You already know I hate Microsoft Word. But it takes actual exposure to generate such a volume of bile, and you probably won't be surprised to learn that there's a copy of Microsoft Office 2011 for Mac on this laptop. Even though I don't use it for writing books, or even business correspondence (I've got Scrivener for the former task and Pages or LibreOffice for the latter) I can't get away from it.
Why?
It's all because of the workflow of the trade fiction publishing business."
The cryptic and impenetrable nature of the MS Word file format - especially its very hard-to-reproduce versioning system - means that writers and editors and typesetters and so on are all at great risk of introducing publisher's errors if they attempt to use anything except MS Word for communication between the various stages of the publishing process.
This has knock-on effects: yes, you can use what you wish (Charlie likes Scrivener) for composing a novel, assuming it can emit MS Word files; but you can't use that tool for exchanging edits. You have to use MS Word for editing. Even though it's not the tool that most people would use for writing a nontrivial work.
Charlie's commenters are (mainly) smart and helpful. Reading the comments is a good thing to do.
Not a happy read, but if you want to work with the publication pipeline, you need to know this stuff.
