I haven't seen the documentary, but I have a background in media and art. There are a couple of ways I could understand this.
The first is the general public's lack of understanding of documentaries as an art form. Documentaries are essentially narratives presented as unfiltered reality ("facts"). Most folks don't truly understand this, or they lose sight of it through suspension of disbelief. That is, they don't know or forget about the film crew, editing, framing, and other artistic choices that form what they see. The illusion becomes invisible; they see only "facts" rather than a constructed narrative designed to guide their interpretation.
Second, filmmakers often use deception as an artistic device in documentaries. Mockumentaries are a pretty clear example of subverting the conventions of documentary filmmaking. It's a bit meta for most folks, so I could see how someone without much media literacy might totally miss this. But it's definitely a very interesting artistic choice given the subject matter.
This isn't confined to "documentaries" - everything we accept as unfiltered 'facts' must be from 'a certain point of view'. Consider the Canon illustration from the article. Those present a man from different lighting, angles and perspectives. No matter how much a photographer might want to convey objective truth, a picture will always be from some perspective and lighting.
The same can be said for the news we watch. Or the history we read. Or the stories we tell each other. In 2026, we have swung too far toward the fanciful end of the spectrum of storytelling. We're now beset on all sides by BS generators (both human and artificial) and it's more important than ever to carefully handle truth in our stories.
But make no mistake - the teller of a story is absolutely crafting a reality for you. It's on you to decide whether you trust the narrator, or not.
Where would Ancient Aliens fall into this lack of understanding?
The achiles heel of the documentaries as a form of propaganda & psyops (aka "narratives presented as reality") is that they have a profound dependence on aural cues for manipulating the audiance. It is difficult to be subtle regarding that intent when sound is involved.
So pay attention to the sound track and adjust your "suspension of disbelief" accordingly.