We can make highly compressed copies of entire websites that each fit into a single (.zim) file. Zim files are small enough that they can be stored on users' mobile phones, computers or small, inexpensive Hotspot.
Kiwix then acts like a regular browser, except that it reads these local copies. People with no or limited internet access can enjoy the same browsing experience as anyone else.
This has been around for a while, but I hadn't heard of it before. I had a spare 96GB on my iPad, so now I have an offline copy of all of Wikipedia on it, just because.