Pornographic content is too accessible. It's impossible for the parents to police this, there will always be one kid with negligent parents that will expose other children to this crap. We are talking 10 year olds here, it's already happening.
My belief is we've slowly let parents get away with not actually parenting and moved that job over to the government and other institutions.
There's many more ways to tackle this that may be more effective and actually seek to educate. How about start with some educational content on why porn is bad for young minds and how to talk to your child about it in a mature way?
It's like nobody wants to acknowledge the elephant in the room and have a civil and mature discussion about it with their children because it's awkward or uncomfortable.