Lets say you live in a world where the world government has decided people are getting too addicted to the internet and ordered the internet to be shut down for 5 years. The 100 GB of storage is all you have (excluding essential system files for your Operating System). You have 24 hours before the internet is getting shut down. What do you download?
Not a .pdf but a .zim that requires its own software to read. And not “it used to”, its still possible now, and new versionnare constantly being added.
Google “Kiwix”. You have to download the reader software, then the .zim file. It’s also cross-platform, available on many platforms, you can even have it on your phone.
Its actually used by various non-profit organizations to spread knowledge in developing/undeveloped countries. The latest version of the entire English wikipedia is like 100GB with photos and audio files, its 50GB with text only.