It is no longer great (it used to be so around Mavericks). Current pdfkit is broken, and renders PDFs blurry, with the effect enhanced on low PPI screens. This holds for iOS as well since the same pdfkit is used, but since the devices running those are extremely high PPI this bug goes unnoticed by all but those looking for it or those with sensitivity to such imperfections. I think the state of PDF rendering on macOS right now is unnacceptable.
Do you have screenshots that can demonstrate this? I'm surprised to hear it, I'm fairly picky about visual quality but I've never noticed an issue with PDFs on MacOS or iOS. Never used a low PPI screen with them though.
It is less visible on a high PPI screen although still there and noticable if you know it exists. Unfortunately I know it exists, can see it and am bothered, so I stopped using my Macbook and left it to collect dust.
I've never seen this issue myself. I'm on High Sierra now.
In Yosemite PDF rendering performance was crap for me in some high resolution documents for print, but other than that it has been flawless for as long as I've been using macOS.
I've only seen the issue shown in the Reddit post (which looks like some rendering lag) in Android actually.
As I said it's difficult to see on a high PPI screen unless you're looking for it. High Sierra, I think, is the first version where this bug was introduced, so you most certainly have it but it just isn't drastic enough a change to bother most people on a Macbook's screen. The rendering lag is another problem that was introduced with the one I'm referring to, which is a separate issue but they are probably related.
Oh wow, that definitely looks terrible. I totally understand not liking MacOS due to that. Thankfully it's much less pronounced on high DPI screens? I've never owned a low DPI macbook so I've never really encountered it before.
Many professors in our department have a MBP, and their LaTeX presentations look bad, just because macOS is bad. I notice it every single time, and sometimes (without me even saying, I just tolerate it, don't make a sound) they themselves do, too, asking themselves whether they've grown that so old or something.
I only have the leftovers of my girlfriend, 2015 MBA, as a macOS device. The PDFs look like crap on Preview and many other ".app"s I have tried. SumatraPDF running on Wine works properly though. Yeah, I'd say Preview simply does not work properly at this point. Shame, but also fun to watch from the Windows's side.
This has nothing to do with that. In fact I am a "Mac user" driven to Windows solely because of this issue.
Aside from blurry PDFs, I also used to like font rendering in OS X and prefer it to Windows but unfortunately it also got screwed up with Mojave after they disabled subpixel rendering.
IIRC the quartz team was involved with Adobe when they were developing the PDF format.