This is good. One of the biggest (in my opinion) failures of accessibility in academia is that everything is published as PDFs generated from latex, which is THE least accessable format in existence (word's PDFs are fine, so it is Latex's fault they are so bad).
Some people provide their latex, which improves matters, but most people don't.
It used to be a problem that you couldn't cut and paste text from TeX-generated PDFs, and I assume this would be a problem for screen readers. I think the dvi->pdf conversion produced a PDF consisting mostly of coordinates and characters (in a non-standard encoding), which PDF readers couldn't put back together into words. This seems mostly fixed on recent pdfs, but I don't know if it's TeX (pdflatex?) or the readers that have gotten smarter.
Funnily, Donald Knuth's AoCP fascicles ship as postscript files, which Preview.app converts to PDFs that can't be copied from.
It's.. inaccessible. Try any screen reader you like. If you are lucky you will get most of the text out with some characters randomly broken. Columns often don't read in the right order, tables and maths are both unreadable.
Good luck reading a scientific paper on your phone period. Many journals are now making available the full text of papers in straight HTML (possibly only for users of participant libraries, I don't know) but that still sucks.
Some people provide their latex, which improves matters, but most people don't.