Especially when you consider that a phone can record hd video, so you can make a player that scrolls through pages and pages of pdfs very fast for example, you record the screen in hd video on a phone and then write a decoder that takes video back to a pdf of the images. Literally the only thing you lose is the ability to cut and paste the text of the pdf and you can even get that back if you trouble yourself to put the images through ocr.

Similarly you could hypothetically exfil binary data by visually encoding it (think like a qr code) and video recording it in the same way.

Even better, there are a bunch of these:

https://github.com/CiscoCXSecurity/QRCode-Video-Data-Exfiltr...