@hankg Yes, perfect compatibility (especially with the OOXML "Transitional" format) is very difficult. Here's a useful article with arguments, to convince people to switch to other formats: https://fsfe.org/activities/msooxml/msooxml.en.html
@libreoffice I definitely do :). I do wish the consistent rendering of word processor documents with MS Office was fixable but since it often falls down to the default fonts not being installable and embedding the fonts is not common for most people (and balloons the size) just have to live with it when sharing documents with others. I'm sure MS has less than zero intention of fixing that and thus ceding supremacy to you, Google Drive, etc. :(
@libreoffice I regularly recommend libreoffice to all sorts of people, elderly, non computer people. It's the best open source office solution out there right now. Thank you for putting the work in.