Comment by goalieca
Apple did create a boolean for that. They call it lockdown mode.
> Lockdown Mode is an optional, extreme protection that’s designed for the very few individuals who, because of who they are or what they do, might be personally targeted by some of the most sophisticated digital threats. Most people are never targeted by attacks of this nature. When Lockdown Mode is enabled, your device won’t function like it typically does. To reduce the attack surface that potentially could be exploited by highly targeted mercenary spyware, certain apps, websites, and features are strictly limited for security and some experiences might not be available at all.
If Pegasus can break the iOS security model, there’s no reason to think it politely respects Lockdown Mode. It’s basically an admission the model failed, with features turned off so users feel like they’re doing something about it.