If you want to be Child Star certified, you need to provide access controls that conform to whatever standard web hosts implement. Parents could be encouraged to buy such products, and this would market well to the parents who complain about what their kids watch on YouTube but also can’t be bothered to _parent_ and actually curate said content.
I think age verification is a losing battle that does what most similar schemes do: make it harder for legitimate users while not having a large impact on the purported problem. All while providing another way to track user data and create huge privacy risk. I’m all for some kind of opt-in or certification system that allows websites that care and parents who care _enough_ to work together to address whatever problem they perceive while letting the rest of us go about our business not even noticing a change in the online landscape.
Highly likely to be the end of free software/general purpose computing, which would be quite a bit worse than identifying yourself to companies providing adult material (in a world where ads haven't corrupted everything, you'd identify yourself when paying for it anyway just like any other e-commerce transaction).