Here is a view that has some weight to it, on the basis of my personal experience as a Fortune 500 technical communicator:
“[Software] Documentation is rapidly becoming a backup for deficiencies in the user interface and user training rather than a complete solution in itself.”
And here is an intelligent blog post that discusses the assertion by making use of a cooking analogy.
But here is the thing: no UI will ever be perfect. Actually, most UIs will always be a “work in progress” since there’s never perfect information about user behavior, updated dynamically through time. Thus user documentation will always be a part of the software industry landscape.