Why do so many people think porn is acceptable when it is so easy to fall into a addiction which is directly detrimental to relationships ?

I have 2 cases in my direct circle of friends. Two female friends of mine are considering breaking up a relationship because their boyfriends watch porn regularly.

My boyfriend lied about watching porn. To me, the main issue isn't even the 'cheating' factor. It is the fact that porn will put unnatural fantasies into his head and I know that when we are intimate he will be fantasizing about those instead of focusing on the present. Worst case, he will bring them up and want to try them and even thinking about it throws me in a fit of anger and sadness. Even worse, he will think that me, as a woman, enjoys being mistreated like actresses in these X-rated videos.
Yet everyone pretends that it is totally possible to keep fantasy separated from reality.

I have watched my fair share of these awful videos myself as a teen compulsively, because I thought it would be a mean to fix my aversion to sex.

I'm now talking from a female perspective but one of these 2 friends I mentioned stopped wanting to have sex with her boyfriend because she cannot stand the fact that he uses porn. This lead them to have an almost non-existent sex life, him to complain that their sex life is dead and resorting to use porn as a means of escape. It is a vicious circle, heavily influenced by the use of these videos.

The worst thing to me is that it is often the partner of the porn user who is blamed. The partner is told to get over it and just accept that their boyfriend/girlfriend watches porn. Then of course, the stereotypical advice that follows is 'why don't you just watch it together ? it is so much fun !'

My opinion is : These x-rated videos have created a lot of problems in our society, but people keep denying it. They are not educational, they don't bring a couple closer together. They merely destroy bonds in the long run.

What do you guys think ?