For what it's worth, the California law, though definitely a result of Meta-funded lobbying, is fairly explicitly anti-tracking: it requires that the OS accept whatever the user enters for their age, and that it tells apps the user's age bracket (under 13, 13-16, 16-18, 18+) and nothing else, and that apps use that and only that for any kind of age-related functionality.

That last part actively pre-empts apps from any of the ID collection/biometrics stuff like Discord's been trying to pull, though don't ask me how that's supposed to work when it conflicts with other state laws that want to mandate collecting ID info.