If you're doing a no nut November, you're presumably avoiding all media since it's full of triggers.
I think the reason people feel better when they avoid porn is because it forces them to do things that won't sexually arouse them. They're not watching music videos, they're staying off social media, they're watching less content on TV that might trigger a relapse and they're spending more time socializing in spaces without women in them that could trigger them.
These are all things that are objectively good for you. You're not getting super powers by not nutting, your mental health and discipline is improved because you're avoiding things that lead you down that rabbit hole of arousal. You're taking the energy you would've spent trying to find the right video and using to go for a walk, hit the gym, cook, read, or socialize with people.