Mac OS on the other hand, has had a broken pdfkit implementation since around Sierra, and any PDF viewer that relies on it (Preview, Skim) has broken and blurry rendering of which there are several reports online. This makes any PDF reader other than Adobe's (which is an abomination) unusable. This has gone mostly unnoticed or ignored as the blur is reduced by the high PPI screens, although it is there and becomes much more apparent on a lower PPI external screen.

This single fact makes Mac OS unusable for me. Windows has its own faults, but at least I can read crisp PDFs on it.