That's interesting, I have the opposite perspective. I'm not a power user in the sense that I use it to write documents, but at work we generate docx files from code (not a good idea) and a significant amount of the time we have perfectly fine files that render as we expect on LibreOffice but break unexpectedly on Word. Sometimes it even renders fine on the web version, but still incorrectly in Word itself.

Edit: I should clarify that I don't mean to contradict you. Just thought it would be an interesting perspective to read about.