Porn addiction is real, and watching porn can have more harm than just puritanical bullshit. Most people that I've watched looking at porn don't just find a video a watch it start to finish. They watch multiple videos, fast forwarding to their favorite parts. Delayed gratification is good for you. Also, porn doesn't accurately depict what sex is like. It can give you fucked up expectations of what sex should be.

If you watch so much porn that you can't have an orgasm without watching it, if you are only aroused by porn that can't exist in real life, if you stop having sex with a partner to instead only masturbate to porn, if you find yourself constantly watching porn even at inappropriate times, if the amount of porn you watch decreases your quality of life... That's addiction.

I think that masturbating is healthy and good for human sexuality, but I think a lot of people could benefit from masturbating differently. Try reading or using your imagination or even just masturbating meditatively, focusing on sensations.