How is a GPS unit any different to anything else that can "suck you in" such that only Apple's system needs a nanny-state-enforced-screen-turn-off?
What next? The car applies the brakes if you look down to adjust the AC controls?
What you're advocating is simply silly. Forced interlocks are not going to make an unsafe driver into a safe driver. All they do is make the system a usability nightmare for those of us (i.e., the vast majority) who understand that "being sucked in" by a screen is something we can avoid by applying common sense to the situation, in the same way we've been doing for years with radio controls, AC controls, GPS units, dashboard dials, trip computers, etc. The Carplay system (like all made-for-car UI schemes like Android Auto and OEM systems) was designed with operation by the driver with minimal distraction in a way that using a phone attached to the dash was not.
Either way you're not going to eliminate poor drivers who do not focus on the road when driving by making the system turn off when the car is moving - they'll simply use something else.