Only because it's documented by mythology. Greek, Summerian, Indian. Others.

Documented in the bible as well. Or the omitted version Enoch. But also partially in the source. Where fallen angels birthed giants by the daughters of men. This came from the Summerian. Totally different story. But the Greeks also had similar pantheons. The sisters were royal descent. Imprisoned becoming the Pleiades. Pleiades in Enoch as well. A different Summerian story despite the sourced similarities. Pleiades worship tracked right to the Incas.

What was it. Okay. Evolution certainly has counter arguments. But it is obvious they actuely struggled with their origins. They needed a narrative linking into the Cosmos the source of their creeds and worship. That worship was vastly different. God's of stone, wood, earth, animals, and elements, becoming stars, the sun, and the planets. As well as their Kings claiming status. Is it fictional, mythological, or fact?

Okay you could put a bull's head on a giant, Minoan, sacrifice ritualistically to that god adorned. Claiming it was a bull, I am sure some were dumb enough, hell there have been. But you had entire battalions of the bull, deer, wolf, bear, lion, and jaguar, etc. They wore the skins, their helmets were animal skulls. They dressed in premium bondage gear becoming Mandalorians. The animal fuckers, I am so sure. But were they. Or was it just a neanderthal in a gimp suit? While the slaves and sacrifices put on a donkey show?

Or were there the Aliens? I mean if they looked at the sky, it's obviously because they came from it right?

Who knows. Nothing completely factual. It got outlawed by the other god claiming dominion.