Why request this? Is there some common wisdom here I’m missing? You should probably include the reason or else this just seems like a weirdly petty request
The HTML page takes an order of magnitude less time to load than the PDF (1 vs. 8 seconds) on my phone.
PDFs are hard to read on phone. The abstract page is better if you just want to read abstract. Some PDFs can also contain large images, which is again bad for mobile if you only really wanted to read abstract.
Also from the main Arxiv page, you can click on the links to each of the authors, see the version history, etc
The PDF has an abstract as well…were you looking for something in particular?
As noted in other comments: viewing PDFs on a phone can be a hastle, and PDFs take a lot more data & time (on slower/mobile connections) to load.
I logged in on a desktop just to respond to this comment in particular, even though I almost always use my phone, if that helps put this in perspective.