HTML still lacks one key feature: a way of storing the entire document as a single file that remains fully functional offline and can be reasonably expected to be widely supported for decades. Research papers are used both for communicating new results and for archiving them. The long-term stability needed for the latter has never been a strong point of web technology.
Indeed, I posted my first paper in 2006. It is still live on the internet in exactly the same format, and I've done absolutely nothing to maintain it.
I'm guessing there are few web pages of any significance which need to stay exactly the same for a long time. Here is one example which I've seen trotted out from time to time on HN:
This is clearly the exception. It seems that maintainers of web pages usually expect that they'll need to maintain and update them for as long as they want them to be accessible, and that's definitely not something I'd care to do for research papers.
You can make an HTML file self-contained by embedding CSS in a `<style>` tag and converting images to Base64, embedding them directly in the `<img>` tag as data URLs. This removes the need for external files, making everything contained within a single HTML file.
I agree that PDF is better than web technologies in terms of stability. I'm not objecting to PDFs being available (like you said, for archive purposes you want them provided by the authors), but to PDFs being the default, and oftentimes only, format available.
Note that ePub is basically just a zipped HTML file, and has become quite common for ebooks. I don’t know how that might be for archiving purposes?
I generally stick to PDF myself, but I do sometimes wish it would be more ergonomic to reflow a 2-column paper for reading on mobile on the go, for example. Also, ePub is easier to read in night mode than PDF recoloring, and seems easier to search through (try searching for a Greek letter in a PDF…).
EDIT: How is the math support in ePub though? Are people embedding KaTeX/MathJax or just relying on MathML, and how is the quality compared to TeX?
