[IshKebab]

Wow so it actually does something! I wish programs would use such vague descriptions. (Or more of them had helpful instant tooltips.)

[maskros]

Linearized (a.k.a. web optimized) PDF files only help for displaying the first page quickly. The rest of the file is still in pretty much random access order.

[e12e]

For what it's worth, there's a format for content like pdfs that's optimized for viewing on screens (as opposed to printing), djvu: https://en.m.wikipedia.org/wiki/DjVu

Oh, wow initial release 1998,now I'm feeling a bit old...