Is porn considered harmful sexual.activity?

I don't have a sex life because I don't have a partner and I don't wish to engage in casual sex so I use porn to quench the biological urge to orgasm. I can't see that's it's harmful because nobody is being forced into it. The actors are all paid well and claim to enjoy it etc. The only harm I can see is that it's so accessible these days on smart devices and so children may access it but I believe that this is the parents responsibility to not allow unsupervised use of devices etc. Views?