> Maybe you need to pay attention if you're dealing with certain European governments these day

Open document formats have been the UK standard for things like .gov.uk for many years. About a decade IIRC. Ignored by some people (notably the Office of National Statistics, of whatever its called these days).

> Most of the world, most of America, most of China, India, etc. haven't even heard of it.

I have come across quite a few non-tech people who use Libre Office.

It has great (some people say better than MS Word with itself between version) compatibility with MS office formats.