Our system is Sharepoint based and I'm not at all convinced that its a good system.
Sharepoint is just the medium or the tool - similar to the way that Word is a tool one uses to write documents in.
It is only - ever!- as good as the person who designs and sets it up. I've seen plenty of bad and plain awful uses of it -just as I've seen some awful documents written in Word (it's not a perfect analogy, but it helps).
It can be done well and I've seen it done well. But to get that, you need someone who understands how to use it and use it well to structure things so that they're useful.
The default is that it's left to the IT person/department who often doesn't and/or to someone with little knowledge of either Sharepoint or the design and use of online documentation. With predictably poor results.
A wiki can be badly done too. But don't conflate the contents with the container.