There is already a pre-existing push to bring attested computing to Linux.
The California law is not the only OS level age verification law passed or in the process of passing in the US.
One wonders if you're being intentionally obtuse.
Its already illegal to show adult material to minors. If they were about enforcing laws properly they'd just do that. For instance a court ruling that adult material isnt allowed on the internet, since you can't effectively ID visitors.
Anyone could just make a fake ID though, so what did they do? Make creating fake IDs a crime. If we can lie about our age to the OS, they'll make it illegal to do that as well.
This is an obvious move to reduce computing freedom.
And because it gives multiple groups extreme power and influence over many things.
And because those groups clearly crave that power and influence.
The internet is the new public sphere and forum, and it should not be possible except through legal judgement to bar or hinder anyone from accessing it.
If necessary, create private gated networks for adult material.
Anyway. You're clearly entrenched for some reason, so I won't waste my good faith effort any more.