Doesn't France already ban depictions of characters that look like minors in sexual situations and also depiction of rape and sexual violence.

In the US obscene drawings of underage characters in sexual situations is illegal under the Protect act "Section 1466A of Title 18, United States Code, makes it illegal for any person to knowingly produce, distribute, receive, or possess with intent to transfer or distribute visual representations, such as drawings, cartoons, or paintings that appear to depict minors engaged in sexually explicit conduct"

Some states explicitly prohibit cartoon pornography

With something like this, a judgement call would ultimately need to be made, yes. That's how a lot of law enforcement works.

If children sex dolls are readily available it risks normalizing the concept of sex with children. Both for potential pedophiles as well as children who browse shein, might get the impression that adults having sex with children is a thing.