Okular

Raised as a usability problem by 7 people on Hacker News over 4 years (2019–2022), in 5 threads.

People raised many different problems with Okular, but no single problem has yet been raised by 3 people in 3 different months and threads.

Unreviewed issues were grouped by machine: Claude Haiku labelled each comment as a usability complaint, named what it's about and summed up the problem in a line, and a small model grouped similar problems. Nobody has checked them by hand. Expect mistakes.

The newest 7 complaints

Smooth scrolling is dizzying when browsing very long PDF reference manuals, and it can't be turned off2022-12-15
Entering text in form fields needs a popup, and keyboard-only completion is unclear2022-05-10
Okular is much slower than MuPDF at rendering pages and navigating2022-05-08
Scroll area is larger than the document and horizontal scrolling is inverted2022-05-07
Won't open zip-named files that it opens fine as .cbz, which is confusing2022-05-07
Editing PDF forms is not very usable, though it works2020-09-22
Slow page loads, high RAM use, and choppy scrolling make reading PDFs frustrating2019-03-25