This is a good thing. It basically contains an entire website, with HTML and assets inside a single ZIP, and a little bit of metadata.
It is incomprehensible why browsers don't just implement it as they already have all the web part, and also ZIP stuff:
The situation is so sad. Ubuntu 21.04 doesn't come with a reader installed by default:
Extract certain pages of a PDF:
pdftk input.pdf cat 2-4 output out1.pdf
Sometimes Ciro Santilli says half jokingly that user interface does not matter.
This software circa 2010-2020 makes that joke not be funny.
How can a UI feel so clunky!
The most aggravating thing is that it is not immediately obvious why it feels so bad.
This is generally good, especially compared to how crappy Evince, the default Ubuntu one, has been around 2014-2020.