I support basically any limits on porn. I’m not religious, but I used to watch a ton of it and it had lasting repercussions on my real sex life. While I would believe religious groups don’t like porn, I think they’re just a part of it
https://en.wikipedia.org/wiki/Illegal_sports
I don't think porn is in this category.
I have not seen any real evidence that would justify the concern, and for the most part the indications are the opposite — there is less harm when it's easier to get.
But for the sake of argument, if it can be demonstrated that some content is harmful, then a ban is justifiable.