We need to document macOS

> Yet Apple’s documentation for users and those supporting users has all but dried up

You and me we both RTFM, but the population at large? Not so much. When computers were in their early days more of the people that used them were willing and even interested to learn a lot about what was going on. Now the computer is a tool used by most people to do specific tasks. Just like I don't care to learn how to fix my car they don't want to learn how to troubleshoot software nor hardware problems with their computers.

So it might not make economical sense for Apple to spend any significant amount of money on employing technical writers.

TFA gives two very disparate examples of documentation failures (basic use of the dock vs service management and the init system). What does the author want to write? A book in the style of the For Dummies series? Something more like the Windows Internals books? Both, everything in between? Some of those surely already exist...

Then your users find that their own memory of where to find things and how to perform tasks is unreliable. Has the system changed or they forgotten it? You're effectively "gaslighting" your users if you rely on this.