I agree with most of what you say. Internet safety is only a cover for other intentions in such laws. But there is a legitimate need to protect kids from the dangers that lurk online. Things like nudity, drugs, violence, radicalism, vanity culture, fake news, etc have a disproportionate and lasting impact on children (and even for adults in many cases. But they at least have an incentive to avoid it on account of being held responsible for their own actions). But it's even worse than that because there are those that specifically seek out and target vulnerable population like children.
Parental supervision often isn't enough, because there are several circumstances where kids circumvent it, the least of which is that an average kid is way more crafty than an average adult. And education isn't enough either, because that only teaches them what is bad. Kids are naturally prone to trying out what they know to be risky actions (which is why they have less legal liability than adults).
What would be a proper and sincere solution to that problem?