Meth is used as a licensed medication against ADHD and leaded gas is still used in general aviation. Everything has benign and evil uses.

those have clear antisocial externalities, so aren't really a fair comparison.

(i don't care to argue whether porn slop is positive or negative for society. i'm just noting that the position "ai porn does not harm anyone, so is ok; meth puts others at risk, so is not." is coherent.)