I get that there may be a target audience, and without a reliability track record this is just speculation, but convenience is only one variable in the equation. We'll need to see it in the field, but I assume that case is not as fail proof as a dedicated dive computer. If your GoPro case fails at 130 feet, you go without taking pictures. If your computer case fails, your dive trip may be over if you don't want to use tables or if you can't rent a computer. Not to mention, you may have just lost a $1,000 phone. Everything has its pluses and minuses and everyone has to decide for themselves what risk they are willing to tolerate. I'm not a seasoned diver and I would still rather rely on a dedicated computer.I think it's good to keep in mind that many different types of divers read these boards. For someone that dives 2 or 3 times a year in the Florida keys on vacation and is already into the Apple ecosystem this may work very well. Someone doing 300 dives in exotic locations probably not so much.
It is absolutely not a PLB. It's a means of communications that is better than nothing for people that aren't into diving enough to buy a PLB.
If I already own an Iphone (I have the new 14 pro sitting in front of me, came today) and an iWatch, adding this case and getting all of that capability makes sense for a recreational diver. It's kind of the same as jacket vs wing BCD, they both work for some divers.