People forget but the Apple Watch was originally market as a luxury product in the same way brands like Gucci and Louis Vitton are. I mean Apple hired the former Burberry CEO to head up their retail stores. This wasn't an accident. There was even a $10,000 edition of the first Apple Watch, which was the stupidest thing ever. Luxury watches work because mechanical watches are essentially timeless. Digital rot ensures the Apple Watch will be unusuable in 3-4 years.
I really don't think the Apple Watch was envisioned as a device for health, safety and fitness/activity. Some of that was present early but if you pay attention to the features and the marketing this really switched a few generations in.
It seems like every generation gets a new feature. One got a (certified!) ECG. Now we have temperature sensors and crash protection. This trend will only continue. If someone can figure out how to get the watch to measure blood sugar it will be an absolute game changer for many people.
There is a huge market for these kinds of devices. Lots of people live alone. Particularly old people have these Life Lock devices to help them in case they fall and can't get up.
Is this really "selling fear"? Preventative medicine and emergency protection is a huge market. These things do happen. At some point I'm sure these devices will be able to detect the early signs of heart attacks or strokes. This absolutely provides value.