No, in the CA law OS controls are part and parcel with app and website developer liability.

They're separate concepts. Clearly, obviously, mandating OS controls is creating liability for OS providers, not service operators. Other states do liability for providers without mandating some other party get involved.

California is also stupid for creating liability for service/app providers that don't even deal in age restricted apps, like calculators or maps. It's playing right into the "this affects the whole Internet/all of computing" narrative when in fact it's really a small set of businesses that are causing issues and should be subject to regulation.