Tell that to Arxiv. Most papers never get printed. Everything is consumed on screen. Yet the layout is completely wrong for screens.
I think browsers should offer PDF reflow as HTML, to adapt to any screen width with optimal font size.
Web designers have the idea that I want a big column of text running down the center and lots of whitespace to the sides, perhaps with sub-menus. This would look OK if I had my main monitor oriented vertically, but I don't and almost nobody does. As a result only about 50% of my screen space is working and I am constantly scrolling back and forth on long pages if I want to look back more than a paragraph or two.
I've developed a deep dislike of commercial graphic designers as a class of people because they took everything that was annoying about magazines and put it on steroids. Many graphic designers hate text and now we have a million interfaces that look superficially interesting but are deeply unpleasant to read.
With academic articles, I virtually never want to simply read them online.
I need to save them for future reference, read them later when I've set aside time, annotate them, refer back to my annotations four months later...
Arxiv (or JSTOR or wherever else) is just where you get the papers. It's not where most academics are going to be consuming them.
(For consumption, a full-size tablet like an iPad, with a stylus or Apple Pencil, is absolutely ideal.)