It's not difficult to understand the job of historians.
In an article discussing a controversial film about the Carthage jail murder of Joseph and Hyrum Smith, Jana Reiss observed:
Actual historians do not demand that their interpretation of an event be unique or iconoclastic. Sometimes their views will support the conventional wisdom and sometimes they won’t. Much of their job is to present the primary sources and allow readers and viewers to draw their own conclusions...
That is an excellent job description that many historians aspire to but often don't implement.
It's no easy task to present primary sources because the sources have to be excerpted and contextualized to be useful, but both of those editorial activities involve choices that reflect the historian's priorities, interpretations, and even conclusions. Too often, historians state their conclusions as facts, as I've discussed here:
Ideally, we would have a system that allowed interested people to see all the facts, in context, accompanied by multiple working hypotheses with their respective inferences, interpretations and biases spelled out. That way people could make informed choices.
But we're a long way from that system.
Instead, historians settle on what they want to believe, arrange the historical evidence accordingly, and then present it as fact in an article, book or video. A competing idea does the same. But the two alternatives are rarely if ever presented side-by-side. Readers of one or the other are naturally persuaded, just as any jury would be in a court case if they heard only one side.
I gave a recent example of that here:
Reiss also quoted the filmmaker before wishing he had followed his own advice.
“If you want to prove a certain narrative, then you’ll only see the evidence that proves that certain narrative,” he says near the end of this interminable documentary.
If only he had followed his own advice.
I couldn't agree more.
Plus, "Reading is exercise, which is why most watch or listen."