No reason to ever use it really. Every time I succumb (fairly rarely), I'm left wondering, "why?" Even if you don't go full NoFap, cutting out porn is a good idea. It is a potent avenue for suggestion, is a pain to have to crane your head toward when standing up, and will bring you to a quicker, weaker climax. It's useless, deeply unsatisfying, and voyeuristic (hey guests!)
In the end though, I like the service porn provides in that a not insignificant share of normscum end up getting porn-induced ED when they try to bed a foid. That decaying old cuxbuxers would rather watch a simulation unfold on a dully glimmering screen than put a hand on their porcine wives.