Wrong.
Let's take a very recent example (and note well, this is not at all uncommon outside of Hollywood, for instance Teshigahara's famous collaborations with author Kobo Abe) Paul Thomas Anderson, directed, wrote, and produced/edited (both the 65mm and digital transfer, in tandem) The Master. It is not at all uncommon for a director to at least collaborate with a screenwriter if not write the screenplay themselves. And most directors would like (although this is sometimes prohibited by the studios, e.g. in the case of Orson Welles) to have creative power if not direct control over the production and editing process.
However, even at this level of involvement we are a far cry from the claim that a single person is responsible for the film as a creative work.
For instance, you're missing a critical piece of the equation: acting. You could easily make the argument the job of an actor is as important as any role a director might have and ultimately it is the centerpiece of so much film as well as the final artist presentation. Even the most controlling directors have limited ability to hold de facto control over this aspect of the film.
Considering all the multitude of complexities of the process, the myth of this superhuman director here is a lot less interesting than the actual process of filmmaking, if you ask me.
A director will do what they can, but there's a reason Orson Welles directed Charlton Heston playing a Mexican.
The author's point is that such arrangements are quite unusual. There are several top-line directors like that - PT Anderson; Christopher Nolan; Quentin Tarantino; Josh Wheedon; Darren Aronofsky; Clint Eastwood; Robert Rodriguez. But they're top-line directors because they're exceptionally talented, and can afford to make fewer films and exercise obsessive control over them, and the investment almost always pays off. I'd say there are 20-25 people working Hollywood who are that deeply involved in the creation of their films. They are a small proportion of the total number of working and would-be directors.
Rare, but not unheard of. Soderbergh likes to do all of those things, though he uses pseudonyms for his "editor" self.
Kevin Smith is such a big fan of doing his own editing that he compares hiring an editor to delegating having sex with your wife to someone else, but that's Kevin Smith, for you.
Kubrick had a DP but like many directors sometimes operated it (or one of the cameras) himself.