An anti-puritan starter kit:
https://www.tandfonline.com/doi/abs/10.1080/00224499.2015.1023427
https://psyarxiv.com/ehqgv/
A couple of studies showing that porn is not associated with sexism. One was carried out by German scientists, another was carried out by Canadians.
https://qoto.org/@olives/110462274531891870
American scientists carried out a meta analysis of 59 studies. They found that porn isn't associated with crime. A meta analysis is basically a study where someone studies studies.
https://pubmed.ncbi.nlm.nih.gov/31432547/ Nor does it seem this is the case among adolescents (although, the meta analysis already pointed to that). Here, the minors who used more porn were less sexually aggressive.
https://www.psychologytoday.com/us/blog/all-about-sex/201601/evidence-mounts-more-porn-less-sexual-assault
https://qoto.org/@olives/110400288665794817
There are even studies (covering a number of different countries) which show porn is associated with less crime, even among criminals.
https://pubmed.ncbi.nlm.nih.gov/31042055/ While an older Dutch study showed there might be worse levels of "sexual satisfaction" among adolescents with porn, a Croatian lab failed to replicate that.
I think that some have concerns about young people and some forms of BDSM. I don't have anything in particular to say about this, other than that sex education might be useful. That's the usual recommendation in science.
It's hard to say exactly why this might be appealing to someone. That said, with BDSM in general, someone might turn to it to deal with complex psychological issues. Censorship isn't something that I'm fond of.
https://www.sciencedirect.com/science/article/abs/pii/S0747563222001637
This one is a meta analysis on sexualization in video games. The study finds that studies tend to pick cut offs where it is difficult to distinguish signal from noise, that increases the number of false positives.
There are also results which contradict the theory of sexualization being harmful. In the end, the study fails to find a link between this and sexism, and this and mental well-being.
I'm usually sceptical of apparent links, as the "scientific pile on effect" (as one described it) drives people to go looking for "links" between porn and "something bad" however tenuous it might be, or methodologically flawed an approach might be (and later, that something is debunked).
Since this is a matter of a certain amount of nonsense, no it is not relevant if the content is "child-like" (also, this is far more likely to hit someone good than someone bad who don't need it), although I would be against sexual content with real children for ethical reasons.
"with so-called "give us ID" arguments"
Who doesn't want to upload their ID to visit a porn site? Well, obviously no one does.