Parents aren't responsible for the harms caused by social media services.
It's the operators who are responsible, and it's the operators who have the tools and resources available to reduce or mitigate those harms. So it is clearly they who should have taken action.
The Ban for U16s is only going to push those who seek it out to darker areas with more risk. And for those who don't its only going to shift the current harm done onto those same children once they are old enough to then legitimately access theses services. Implementing the ban isn't going to fix a systematic failing of social media providers. This is the first step in a thinly veiled plan to re-implement the already unpopular UK Digital ID plan, under the guise of "protect our kids".
I think it's reasonable for governments to signal a decision like this that parents can ultimately choose to bypass. So it's both to explain the harms and posture to reduce those harms to children, and to leave the final decision to parents.
It's the operators who are responsible, and it's the operators who have the tools and resources available to reduce or mitigate those harms. So it is clearly they who should have taken action.
But they haven't, and so here we are.