It really pisses me off when some kind of public service demands documents in the format docx or expects one such document to be filled and uploaded. They can't truly assume that every single citizen must have a license of Microsoft Office.
LibreOffice, remember?
[1] https://en.wikipedia.org/wiki/LibreOffice
It has various levels of adoption in individual European countries and regions (in the EU and beyond) with a number (such as the UK) making it the standard for document exchange https://en.wikipedia.org/wiki/OpenDocument_adoption#Europe