How does looking at pictures of naked people having sex harm children?
(I don't think the idea of restricting access to some websites based on age is inherently bad, I just don't see a way to enforce it that isn't more harmful than useful)
This is just another typical cultural issue that people cannot agree on. My problem with these laws is that they force morals upon the population that are not necessarily widely accepted. e.g. 99% of people agree murder is wrong, but what % of people agree on what 'porn' even means?
Perhaps the vast majority of people don't have a good idea precisely because they have watched porn from a young age. I know that's the case with the young adults of my generation (26 years).
So to answer your question => Yes; not watching porn is much healthier than watching.
> [porn] might provide information to those who may otherwise not get it
Porn doesn't teach you how to have sex, it teaches you that sexual feelings are a commodity you can take.
I used to buy into the whole "porn addiction" idea and though I was, but when I dropped it cold turkey back in college I just found other unhealthy coping mechanisms. Until I went to a professional and got on track towards fixing my health issues, then my "porn addiction", "video game addiction", "work addiction" or "browsing memes/hn addiction" or whatever else I had just went away, and I can now do all those things without overdoing them and without damaging other aspects of my life.
As such, I don't think any kind of porn addiction is the source of problems, but more of a symptom. I think this is generally true with any kind of addiction, but substance abuse has a harsher physical component to it with withdrawal. All the other "addictions" without a physical element are rooted in attempts to get some form of pleasure (dopamine, etc.) because of other problems (stress, depression, anxiety, loneliness), and once those other problems are solved the "addiction" tends to go away on it's own, unlike with substance abuse.