This text is almost unreadable to me. The characters are actually touching one another, blending together.
If anyone wants more punishment, the rest of the document is here: https://ista.org/docs/1Aoverview.pdf
Also, relevant xkcd: https://xkcd.com/1015/
Can confirm it is a font substitution issue. When I open the PDF a different font is used (note the very distinctive “r”) which has much better (but not great) kerning.
It’s better, but still horrible in its own special way.