Indeed, Kiwix is the proper solution for anyone who cares about knowledge access in places where internet connection is spotty. Given the file format it uses (zim) is compressed, and meant to be accessed compressed to pluck a specific article, you can have all the content of English's wikipedia without images and videos in just 36GB. Plus, the specs of the file format are published and it's easy to build your own implementation, I did it for my needs.

It's also great for privacy maximalists : I have wikipedia, wikisource and wiktionary in two languages locally, which means that most of my searches never leave my computer.

Kiwix/openzim don't provide only mediawiki projects either, I've recently downloaded stackoverflow's content (although, I'll need to build a dedicated search engine for it to be really usable).

You can have a look at the incredible amount of available content there: https://wiki.kiwix.org/wiki/Content_in_all_languages