While I do think realistic stuff should be illegal, no question, with the loli/shota/whatever, you’re just opening a can of worms that could be applied to other things too, and some already did.
Regulators used the very same “normalizing certain sexual acts” to try and censor more extreme form of porn and/or the sexual acts themselves, and partly succeeded in the UK. Sure, scat is gross, many like that exactly due to that. One could even talk about the health risks too. Same with fisting, which is too extreme for many, supposed to be extremely painful because many people’s only exposure to it was from Requiem for a Dream, and has some associated health risks. However, a lot of it is some misrepresentation of the truth, with scat isn’t that big of a health risk if you have a good immune system (rest can be mitigated with precautions and moderation), and fisting isn’t inherently painful (source: me).
And the same is true about loli/shota. The terms aren’t just applied to actual underage characters, but for the “short adults” common within the VTubing scene, many of which are also shorter in real life (obligatory “of course not all”). Some of those other characters are also adults, that have exaggerated, almost child-like physique. Most of it however is still just some depiction of children, and otherwise I can understand why some wants to abstain from even the “adult loli/shota” stuff. I remember when pubic hair removal was becoming mainstream, and many, like radical feminists, feared it would normalize pedophilia, I even got called a pedo by a pubic hair connoisseur for not really liking it. I also don’t really want to talk over victims of CSA, many of who want it banned, many of who want it legal.
As for normalizing: The greatest normalization is done by pedos getting into the fandom to recruit others, and entertain the idea of a lower age of consent. For a long time, we threw out these motherfuckers from our community. But then 4chan happened, and suddenly these very same people just started screaming “it’s just an edgy joke bro”, so at one point people trying to keep these creeps out of the anime community in general became villainified, and with gamergate and the culture wars hitting the scene, “gatekeeping the normies” became the priority, so these sick fucks became a feature, which created in the anime community
a nazi/pedo/weird gatekeeping free space,
and a space that doesn’t moralize about loli/shota.
I had a lot of connections to victims of CSA, most of them were teens, none were groomed by loli/shota (everyone’s mileage will vary on it, likely different in the age of the internet), but by either some non-pornographic work featuring a teen girl and an older man (usually in historic setting), or just by the perpetrator likening a 25+yo guy (often they lied they were way younger) going out with a 14 yo girl to her parents age gap (I’m in Hungary, where that’s technically legal🤮). Usually a simple “that big age gap isn’t okay in your age” talk did wonders, unless the only way for the girl to eat that day was to go out with that guy.