Can I ask a question here without being flamed?

Isn't this the best option? The reason to push this onto Operating systems is because they could in theory do the verification completely client side without involving a remote service.

And if applications can then just use that age check API provided by the OS it would greatly increase the privacy of these types of features.

(I'm not at all trying to say I support these sorts of checks, I'm just asking this under the assumption that these age gates are here to stay)