>decades...where docs are copious but wrong about 50% of the
>time.
Nice summary of the status of Linux documentation. Not sure if it's really 50% wrong, especially the man pages make an impression of over-corrected but the usefulness depends on the tool and is completely random. But yeah, online documentation, classical tutorials are usually useless. When I see a tutorial, I close the tab. They just lead to dirty installations. If a tool needs a documentation, there might be an alternative that needs none. ;) But seriously, a lot of stuff on Github is obvious to use.
Not sure about the macOS. Having changed from Linux to macOS as my main (laptop) OS, I first noticed the unusual BSD tools. So I installed GNU tools on my first year OS X. Now I just use the BSD tools, some I even prefer over the GNU versions. But I guess the stuff that has been developed by Apple has no docs at all..