“Documentaries” on YouTube and not the best. Most of the time the images and background isn’t even the specific topic of discussion. For example, showing the wrong plane or car when the video is specifically about a certain fighter jet or war.

It made me realize the larger studios and productions have access to lots of accurate “fluff” like historical reels. They even have budgets to take real crews to locations. Makes me rethink the amount of time I spend on YouTube.

I consider "posted on YouTube" the same as "posted on the Internet". Youtube is basically a comm channel, they don't vet for accuracy nor do they claim to.

Look instead at the channel. Some channels make serious efforts to cite their sources and justify their claims; others do not. It's hard, but where you can, try to prefer the first.