Sounds like a good idea. Children should not visit those sites.
Maybe yes, maybe no, it's irrelevant.
You don't get cancer from porn, and you can't porn yourself to death. Information and substances aren't equivalent, so let's move on from here.
How about e-cigarettes? I see some similarity to pornography; they’re arguably both not harmful — vaping doesn’t cause cancer; it was invented as a safe alternative.
https://blog.dana-farber.org/insight/2018/07/nicotine-cause-...
>This does not mean that nicotine is completely safe. The U.S. Surgeon General has found that nicotine exposure during pregnancy can harm the fetus and have lasting consequences for brain and lung function in newborns, according to the American Lung Association. Nicotine also has a negative impact on brain development in adolescents, according to the Surgeon General.
There's a reason we have FDA.
I don't want the government snooping on my porn habits (and probably leaking them, given past government system breaches).