Comment by codedokode

> Digital verification exclusively on-device doesn't work because addons and alternative applications make it possible to bypass those checks.

The OS on device with "isAdult == false" would allow only to install apps from app store, which are marked by developers as "safe". Alternative apps which do not respect isAdult bit won't be marked as safe and cannot be installed from an app store. And sideloading or bootloader unlocking, of course, will be disabled if the phone has "isAdult == false". There is no simple way to bypass this protection, even for a skilled adult, because modern OSes are closed-source and digitally signed and you don't have the source code or private key.

> The point of the Act is that the UK government no longer pretends to believe that the "I am 18 or older" checkbox is actually stopping anyone, and that there are no better alternatives.

The better alternative is "isAdult" bit that is stored on device, cannot be changed by the user, and respected by an OS and white-listed apps. It doesn't require sending one's IDs or photos of one's face anywhere. It is better in every aspect and requires ZERO costs from website operators and app developers for compliance. The only ones who will bear the costs would be OS developers, like Apple or Microsoft who have a lot of money and engineers to implement this.

> The point of the Act

I glanced through the overview of the Act and it seems that the main point is in letting the government (Ofcom) to remove online content promptly without long procedures.