I do think that internet access can be harmful, but social media seems far more damaging than porn. The bullying on sm can be truly dreadful, and kids could be harassed every day, every hour, and groomed as well, and it can literally be fatal at times. There has always been porn, and kids being exposed to sex between all kinds of animals, including humans, used to be an everyday occurrence. Yes, the amount of porn kids come across has increased, and some of the, shall we say, odder variations of the theme, may be harmful to some. But our views on rape, for instance, have changed for the better quite dramatically, compared to only a few decades ago, and the idea if consent has become far, far more prevalent during my lifetime, as has sex ed. And this is true on the internet as well as irl.
Unsupervised social media, on the other hand, can be a dangerous place for kids.