Thank you for reading, @markush.
What you are suggesting makes sense, and I can understand why this kind of social policy would reduce crime. The next step for society would be to investigate the deeper psychological reasons for these dynamics.
Regarding the world being a mess before porn, I agree. I'm not suggesting a causal relationship between porn and abuse; but a symptomatic one.
I can imagine that porn may also reduce abuse on one hand (similar to the situation you describe where it provides an outlet for those who would otherwise abuse), while normalizing abuse on the other hand (depicting abuses as acceptable).
The central point I hope to communicate is that, for me, my porn use was a symptom of earlier abuse, and served a social function as a painkiller. Now I have taken steps to heal the pain, I no longer need it.
RE: Pornography and Me: How and why I escaped.