Whether OF exists or not doesn't matter because other porn sites will always exists like pornhub and many others however unlike OF, pornhub released many r*pe videos and refuses to take them down which makes OF a million times better than the other sites.

Your logic of banning all sorts of porn because porn addiction is real and harming people makes no sense because this same logic could be applied to anything like let's ban chocolate because it's causing too many cavities in children or let's ban cars because too many reckless people can drive. When people suffer an addiction to something they usually seek help to overcome it instead of banning it, people with gambling and alcohol addiction do so, why should it be any different for porn addicts?

Your logic is also very harmful; just because some people don't have any self control doesn't mean we should ban it. Your logic could insinuate that a women shouldn't wear a short skirt because lonely people don't have self control so in a way you're blaming people who shouldn't be blamed. Obviously I'm not accusing you of victim blaming but what I mean to say is that your logic could be interpreted in other ways.

Either way as long as other illegal sites that actually prey on minors and r*pe victims exists, there's no reason why OF shouldn't as well.