They've made it so. By it being left as the biggest "mostly untainted" bastion of escapism and media left to the world. Their plans only work if you have no other option available and therefore are forced to compromise and consume their slop, to let it slowly program and brainwash you into their narratives.

Though I shouldn't have said anime, but more "Asian Media as a whole" because the same thing applies to things like FromSoft games or Mario. Which is why they are so obsessed with trying to shoehorn themselves into controlling those in some form, such as Nintendo having to directly force Illumination to remove their bullshit from the movie multiple times.