I find I enjoy watching documentaries and reading technical/history/biography books often more than fiction. Because fiction is, ultimately, fake and manipulative.
I'm reading your comment as implying that fiction is more manipulative than nonfiction? If that's true, I'd be curious to hear more about your reasons for that. Don't mean that in a challenging way, this is just a topic I've been thinking about.
The problem I have with biographies and documentaries is that they overlay order and narrative on this 'messy and unpredictable' reality. If anything, that's more manipulative than a good novel that is rooted in deep research/domain knowledge and that doesn't claim to be 'objective'.
Historical accounts are always biased, usually according to the political correctness of the time they were written. For example, the Founding Fathers went from hero to goat to hero to goat and are now morphing back to heroic status with the play "Hamilton".
Civil War heroes are goats today, even having their memorials removed.
Edison has gone from hero to goat. He'll be a hero again in a few decades.
It's the job of a professional historian to try and discern the truth from all this. But whatever truth there is in fiction is impossible to determine if you know nothing about history.
Of course they are. The challenging part is reading different accounts of the same events, and attempting to discern the truth. For example, was Edison a good guy or a bad guy? Did he invent the lightbulb or steal it? And if you find something interesting, you can dig into it and find out more. Not so with a novel.
Fictional universes evolve into 'canon', where certain explanations are correct and others are dismissed. Star Trek, Star Wars, etc., famously have 'canon'. People get wrapped around the axle arguing canon. This is ridiculous, as it's all made up nonsense.
Good point on reading multiple viewpoints. As for fiction, there are a few writers who say true and interesting things about the world but they don't write Star Wars novels. I'd say "Disgrace" by Coetzee and "Demons" by Dostoevsky are examples.
You do realize 'fiction' is more than just Dan Brown and Star Trek, right? Some of the best novels I've read are basically historical/biographical accounts that just don't pretend they're anything but one person's biased take on things.
Instead of reading historical/biographical fiction, why not read the real thing? For example, read "Stuka Pilot" by Rudel. It's an account of fighting in WW2 that would be dismissed as ridiculous if it was a Hollywood movie, but it is all real and documented.
Another is "Reach for the Sky" by Bader. Chuck Yeager's biography is also a treat.
Then watch that absurd "Flyboys" Hollywood fiction. What a piece of trash in comparison.