> in the US, pornographic images are only restricted when they document someone being abused

I don't think this is true. Since "child" means anyone under 18, "child porn" therefore includes teenagers sexting their boy/girlfriends; some of those relationships could be called abusive, but surely many could not be, unless you think a teenager taking pictures of him/herself is inherently (self-)abusive. But I'm sure no internet content moderation policy, nor likely any police raid, would look into the background of a nude picture of a 14-year-old and determine that no abuse was involved and therefore the picture is permissible.

See https://pubmed.ncbi.nlm.nih.gov/22144707/ . "The cases involved "youth-produced sexual images" that constituted child pornography under relevant statutes according to respondents. ... US law enforcement agencies handled an estimated 3477 cases of youth-produced sexual images during 2008 and 2009 ... Two-thirds of the cases involved an "aggravating" circumstance beyond the creation and/or dissemination of a sexual image. In these aggravated cases, either an adult was involved (36% of cases) or a minor engaged in malicious, non-consensual, or abusive behavior (31% of cases). An arrest occurred in 62% of cases with an adult involved, in 36% of the aggravated youth-only cases, and in 18% of the "experimental" cases (youth-only and no aggravating elements)."

So the idea is that sexual activity with minors is coercive, and that trading in pornography is sexually exploitative and a minor cannot consent to be exploited. I would disagree with that on principle, however if it were to be established as precedent that it is not it would be a huge loophole for people actually exploiting people coercively, and I'm not entirely sure how to square that myself.

Er, you say sexual activity, but I was talking about sexting, which generally means partly or fully nude pictures of oneself—taken by oneself, alone—which don't depict sexual activity (except possibly masturbation). Those pictures will generally be classified as pornography—as my link said, they "constituted child pornography under relevant statutes according to respondents [law enforcement agencies]"—and producing them is an offense for which one can be and sometimes is arrested, and it is up to the police to decide not to enforce it (similar to speeding).

Then, if, say, someone still has naked pictures from age 15 (of herself in her bedroom alone) when she turns 18, and decides to start selling her own pictures online (or even posting them for free), and some guy buys them, and at some point the guy gets raided and the police find those pictures... I'm pretty sure the guy will get charged for possession of child pornography based on those pictures (assuming one can tell by looking that the girl was 15), and "no one abused this girl in the process" will not be accepted as a valid defense in court.

>FYI for point 1 this is not true, in the US, pornographic images are only restricted when they document someone being abused, drawing, animation, and even role play are legal.

The analysis I have seen in the past disagrees with this, but honestly I am not looking to plug the necessary keywords into a search engine to find a source. I believe the specific example was regarding deepfaking completely fake computer generated children's faces onto adult porn.