I'm not mac dev but wasn't apple all in on objc back then and these days it's more swift? that is pretty big shift, I'd assume for the better for most parts.

I prefer Swift as a language, but Apple's developer documentation back then was clear, detailed, and overall excellent. Occasionally I felt like I was reading a classic CS text rather than a manual. I could always find the guide on the particular facet I was looking for within a few clicks.