Fictional Characters as Source-material-divorced Simulacra
When I studied abroad in Japan I took an Anime class (because "when in Rome" or whatever) taught by a guy named Sean O'Reilly who was originally from Boston (lmao).
Like any college film class it was mostly just a way to watch interesting movies twice a week while being forced to write superfluous analysis essays for homework. But one lesson really stuck with me in the years since.
It was taught through the lens of Neon Genesis: Evangelion, but applied across nearly all modern media. The lesson centered around the idea that character archetypes and designs can become a simulacrum of themselves. That they can become detached from their source material and can gain fans and sell merchandise completely independently. The greatest examples of this are in the characters for Rei and Asuka. Both as characters that drive massive fandom and interest largely divorced from their literal source media, but also as core design archetypes that expand way beyond the sphere of Evangelion. Just think of how many fiery redheads or emotionless short haired characters you've seen. They're all the same, not only because of "tropes", but also because they represent this larger simulacra. They're characters that you can know and be a fan of without even needing to be familiar with where they came from.
This part goes beyond what was in the lesson but I think is still relevant:
These simulacrum tend to provide a pre-baked familiarity and comfort when assessing new media. You know what you're getting into when you see red haired anime girl, or a five-o'clock-shadow-ed combat man. They're all the same character. But they're also all different. The simulacra is what provides that basis of familiarity.
Also also, it's hard to talk about all of this without also recognizing how horniness plays into everything. TikTok has exacerbated the existing situation and is a great example. The monthly changing of the guard from one in-vogue cosplay to another for e-girl thirst traps is largely disconnected from the actual source material. The simulacrum of these characters drives engagement on its own.
To wrap it all up somehow, since these characters exist in capitalism you end up with these designs catered to work, not only as characters in the source media, but also to stand on their own and gain fans (while selling merch) outside it too. They're contextless distilled vibes where everything you need to like them is visually apparent at a glance.