Many countries criminalize the distribution of child porn, irrespective of whether it's real, drawn, sculpted, or sometimes even written.
If you are caught with loli hentai manga in New Zealand, expect the law to treat you like the chomo you are.
The reason why blanket bans are implemented is not just to punish actual harm, but to avoid creating a demand for material that harms children.
In the USA this kind of blanket ban, though desired by a majority of citizens, has historically not been feasible due to "that pesky First Amendment". So we say it's not about banning speech, it's about banning the abuse of children. And then we say that children get re-abused every time someone procures, distributes, or views this material. (Except when the FBI does it.) And then we're into semantic hair splitting of when exactly child abuse has occured: what if it's Bart Simpson? What if it's an AI deepfake? A photorealistic render of a fictional child? A Shadman cartoon drawing of a real minor e-celeb?
Other countries have eliminated this problem by banning the material altogether irrespective of whether it depicts real or fictional persons, whether photographed, drawn, or computer synthesized. Before 1969, this would even have been possible in the United States. The PROTECT Act gets us closer by criminalizing any material that flunks a Miller obscenity test, which the Supreme Court has ruled is NOT protected under the First Amendment.
The harm is supposed to be to children.