Unless you would would uncritically believe a random person today who claimed on TikTok to have seen a UFO, why would you uncritically believe accounts from people who had a vastly worse understanding than us of how the world works? And that's if you start out by assuming they're supposed to show aliens, which there's pretty much no evidence for.
If you're going to believe them when they tell you aliens visited them, you also have to believe them when they tell you the mountain god eats the sun during eclipses, or that the lightning striking near their cave was evidence of the sky god's displeasure with their lack of human sacrifice.