Print or screen: pick one.

If you want something to print beautifully, you take the time to put the figures and pictures exactly where you think they fit. If you want something to be read with arbitrary text sizes, you hope they'll show up somewhere near the relevant text. Treating a book as an ebook, or vice versa, will always be a compromise.

Easy choice: screen.

Horses for courses. For novels? Sure. For reference books with a lot of photos and diagrams, I still prefer print to whatever would result from a "reactive" layout reacting to my current screen and font size. Maybe they could be rewritten as interactive "apps," but that's a lot more work, opening a whole new can of worms.

The new ACM format is attempting to fix this for academic publications. I believe it generates HTML and should look better across devices (and be more accessible).

I haven't seen that happen yet though...

I haven't heard of this "new ACM format", but for years I've wished for a PDF2 that incorporated lessons learned from PDF and web pages for print, ebooks, web on multiple screen sizes, and non-visual readers (for the blind but also for anyone who would like to "read" a book or paper while driving or jogging).

A "multi-view" format that could be viewed as full page layout (both scrolling and paged), small screen linear, audio-only linear, or machine-readable (full, deterministic text sequence, tabular data, alt-text and tags for images and charts, etc.) All pages, images, fonts, etc., would remain encapsulated within a single file.

The closest I've seen is the latest ebook format, but that doesn't have anything close to the power of PDF to lay out a proper textbook or magazine article page.

Isn't that just HTML?

Markdown comes to mind

That's true, but not unique to PDF. Any longer document is "basically unreadable on smaller screens".

No way. A Kindle is great for reading books, but text in a typical PDF is too small to read. Reading on a phone is a bit more annoying but totally reasonable with dynamic text layout.

Sadly PDFs are usually just a series of graphics instructions for drawing stuff (including text) at specific sizes and positions, on a page with a defined size. It's an inherently hostile format for reflowing text, although I think some PDF viewers can do that to an extent. The PDF accessibility spec defines an optional, more DOM-like document structure that a compliant viewer could use to reflow text, but in my experience even the apps that produce that structure don't populate it with enough data to make reflowing reliable or easy to implement. Pretty much every format is way better for reflowing text than PDF (Kindle, ePub, HTML, etc.).

+1 also, kindle != web.

Koreader[0] can be sideloaded on Kindles, Kobos and other devices, and is good at making PDFs readable on such devices.

[0] http://koreader.rocks/

Thanks, I’ll have to check this out.