It's an open standard that could lead to tighter controls on devices in the future. That's an extremely slippery slope. Wouldn't it make more sense to require age verification for social media platforms and outlaw online gambling? Why deanonymize the devices themselves? I suspect it has nothing to do with protecting children.
If I had to speculate, I think the people in power are scared of how much on-device AI could empower the masses and they're laying the groundwork to curtail it right now.
If the social media platforms are the problem, then why control the devices and not the social media platforms? Makes no sense unless there's an ulterior motive.