Banning ISN'T a solution, as you mentioned eloquently above, however I tend to think all pornography on the internet should be completely behind paywalls so that random individuals can't stop by Pornhub impromptu for a quick session.
Addicts of any sort are going to find their way into obtaining their particular poison. I think, however, that the ease of access is the primary issue here, not the existence of the subject matter itself.
And how can ease of access be prevented? So long as the internet is open, there will be people out there who will put up easy access porn.
Hence why I suggested a paywall for legitimate distributors of adult media, however there are also the issues of torrenting/peer to peer downloading and etc. I think a lot of individuals would be deterred from going down those avenues, though, simply because it can be monitored/caught by one's internet service provider... which can land you in a whole host of copyright infringement issues.
This idea would still have many of the same effects as a ban, though not as extreme. It's a "light ban" where there are approved or "legitimate" sources. A black market of "illegitimate" producers and distributors would quickly form. Just think of the cigarette black market.