No, I’m pretty sure I fully understand you. I’m just pretty sure that people are either making it up or ascribing normal, terrestrial things that they don’t understand as fantastical things. There aren’t ghosts, spirits, dragons or aliens that have secretly visited earth but choses not to make actual contact. My point is that all of those things are equally unlikely. I assumed my over-the-top absurdity made that clear.
And I feel like you might be underestimating literally all of the world if you think these things are actually aliens. You’re implying that they would assume something they don’t understand is some mystical nonsense. That “almost everywhere that isn’t the US, even today” is superstitious and wouldn’t know what aliens are.