If the API didn't suck, there wouldn't be such video there.

Also WWDC videos are infamously used as reference because often documentation suck. And it shows.

Absolutely. I did a little bit of iOS development at some point and was genuinely shocked by how bad the documentation was and by how often WWDC videos was the best documentation available.

To give a concrete example: At WWDC20 Apple showed off a new Core Data feature called "derived attributes" [1]. Only many months later did they add the bare minimum of written documentation covering a fraction of what was shown off at WWDC [2].

1: https://developer.apple.com/videos/play/wwdc2019/230/ 2: https://developer.apple.com/forums/thread/120159

But you know, Apple is a struggling company that doesn't have enough money to pay devs for documentation. /s obviously.

Microsoft may produce some half-assed software but at least their documentation is generally pretty solid (and easy to find).

I don't really see how that makes a difference. A talk with the title "my API demystified" is an equally bad sign.

> A talk with the title “my API demystified”

But that’s not the title of the session.

The title of the session was “Background execution demystified”

Background execution is a computer science topic that many don’t understand well. Much like font antialiasing or other computer science topics that people don’t have to deal with daily.

Note: I’m not saying Apple APIs are great. I was just originally pointing out the context of your post.

I spent an afternoon watching and re-watching this video just to figure out how the otherwise-undocumented behaviors of the API work. It was exclusively about Apple's implementation, and not in any way about the general CS topic.