https://verilymag.com/2017/07/causes-of-divorce-effects-of-w...
https://www.science.org/content/article/divorce-rates-double...
You can find plenty of pro porn propaganda out there too. They want to fill the channels with, at least, uncertainty.
But use your own brain and human experience. Do many women you know celebrate porn use by their husbands/boyfriends? That it doesn't bother them at all?
I don't need a study to tell me a hot stove burns. I've experienced the pain myself.
How is this in any way relevant? Touch stove -> get burned is an immediate and consistent causality chain. See porn -> get divorced is not an immediate response in almost all cases, nor is it even consistent.
Frankly the whole causality sounds a lot like people getting married before knowing important things about thier partner. (and yes if you are going to divorce someone over porn watching, it's an important thing to know about them going into the marriage, you should at least ask. On the other side, lying about it and trying to hide it are bad too - maybe honesty is a good idea in marriage situations... who knew?)
It's a metaphor. Somethings can be clearly understood, by individual experience, without needing a body of citations. As clearly as a burn.
You misunderstand the nature of the personal and relationship damage if you think that divorce is the principle issue. It is but a symptom of the unhappiness that is rooted in porn use.
Citation needed.
Usually a man's porn collection is not "public". If one shows it to his wife then ...