Apple's architectural/design intent documentation is sort of hit or miss. The biggest issue (IMHO) with overall architecture documentation is too often it doesn't make it into written documentation. The key insights are sometimes the middle ten minutes of a WWDC keynote or presentation.
If you didn't attend that WWDC session or pour over all the recordings you've missed that particular key concept. So you're then sort of feeling your way around some new technology and making it work but it's not as efficient or elegant as if you had the whole picture.
Because there's so little documentation time and Apple does not (as a rule) do engineering blogs or similar there's not a lot of of opacity into inner workings or designs. From the outside there's a lot more reading of tea leaves than you see for other platforms.
I see. Engineering blogs do fill some of that role in Microsoft’s stacks. This is not completely ideal either. Blog posts are frozen in time, and newer articles tend to only describe the deltas. So to get a current understanding, you also have to puzzle together various bits and pieces. But at the very least, blogs are easily searchable.
While blog posts aren't ideal they're (like you point out) better than nothing. But blogging goes completely against the grain of how Apple operates internally. The WebKit blog is a singular notable exception because that's a highly visible Open Source project. Even the free-form Q&A portions of WWDC sessions are rarely as frank as they should be in terms of usability.
No blogs is fine, that's just the corporate culture, but no blogs and no good up to date architectural documentation is a huge problem. It leads to cargo-cult understanding or complete misunderstandings by outside developers. Hell, it leads to cargo-cult understanding by internal developers.
If you didn't attend that WWDC session or pour over all the recordings you've missed that particular key concept. So you're then sort of feeling your way around some new technology and making it work but it's not as efficient or elegant as if you had the whole picture.
Because there's so little documentation time and Apple does not (as a rule) do engineering blogs or similar there's not a lot of of opacity into inner workings or designs. From the outside there's a lot more reading of tea leaves than you see for other platforms.