Considering the "Ancient Alien" stuff mostly exists because people find it more plausible space aliens did something than brown people in the past that we find

Considering the "Ancient Alien" stuff mostly exists because people find it more plausible space aliens did something than brown people in the past that we find complicated to explain nowadays, I'd say you're not too far off. There is a lot of projection in a lot of so-called sci-fi media, especially with regard to "alien invasion" tropes. The idea that some foreign group arrives with vastly superior weapons and technology we don't understand to wipe us out or enslave us for some ulterior motives that possibly don't even make sense to us would sound a bit on the nose unless presented in a politically race-neutral way to a demographic of the historically culturally dominant group. There's certainly a degree of fear of revenge to it, though less blatant than in early zombie media (where zombies were more strongly associated with "voodoo" and implicitly a punishment for colonialism) or even exploitation/horror media like Cannibal Holocaust or Heart of Darkness (and a lot of the media inspired by it like Apocalypse Now) where the threat is explicitly more "primitive" (in the case of Heart of Darkness the threat being a form of contagious primitivism itself) but the dominant group (usually white people) are put in vulnerable positions through circumstance. It's no accident that Lovecraft was legitimately extremely racist. It's important to remember though that humans are not intrinsically racist. Tribalist maybe, but kinship can spread all superficial boundaries of appearances and cultural differences. Whiteness is not a question of a specific skin color or ethnicity but the absence of "non-white" identifiers and thus ultimately just as arbitrary as Roman citizenship during certain time periods in what we now think of as Europe and Northern Africa. And of course just like Roman citizenship, those delineations exist because they benefited the dominant group within (or the colonial administration) by providing an other.