Reality check: Children have many and useful opportunities to use devices in all kinds of situations away from parents.

Useful situations. On devices parents don't control.

Expecting parents to follow their children around 24/7, in case they access some adult site from a public or friend's device they don't control is beyond ridiculous.

Privacy protecting, anonymous validation of 18+ status solves the problem, in a way that doesn't require unrealistic "parenting" behavior, protects everyone's privacy, and is even helpful to responsible adult sites.

Condescendingly telling parents to "parent" in a way that is virtually impossible, instead of helping, is just rolling out the red carpet for alternate non-anonymous age verification legislation.

Zero knowledge tech, like end-to-end encryption, protects privacy.