It's not crazy to have a device-independent presentational document that also contains enough data to enable some device-dependent rendering of its text and media contents.

I read a boatload of 2 column PDFs on my phone. Liquid Mode has been on PDF Reader on Android for... it feels like a year now? And it's fantastic. Without it I have to constantly pinch and zoom and swipe to the upper right to start a new column, etc.

I hate PDFs, but if I want to read a document I've stored in print fidelity from the 80s on my phone, Liquid is rock solid.

That would be the case if a PDF was solely used for print.

In the digital realm though, a PDF should also be accessible to screenreaders for the blind, people with sight problems (increased fonts, contrast), dyslexia, etc. Those already require alternative representations.

And of course nothing bad about having the best of both worlds! A format that is pixel perfect when you want it too, and adaptable for easier reading when you don't.

> For device-dependent rendering, we have HTML.

It does not sound like the goal is device-dependent rendering, though. This is exactly parallel to Reader Mode, which is a temporary user toggle. The goal of PDF is still to produce documents that mirror print-ready layouts, something that HTML has never really accomplished. Whether you want to consume the documents that way will now be up to you.

> For device-dependent rendering, we have HTML.

Say that to those who create PDF files for things that should be web pages. That behavior is not going to stop anytime soon.

This is kind of funny to me since what is now the iOS Core Graphics framework started out life as a PDF rendering engine.

Sadly no one really publishes books as HTML.