I can think of three potential serious uses without even trying hard:
Home automation: not an issue for me. I arm the alarm when I leave using my key fob (can use an app on the phone if I prefer, but the key fob is easier). Turning on the pool lights or spa jets can be done easily with the phone.
If I want to turn on/off the light in a room, I have conveniently mounted electrical switches on the walls I can easily flip with little effort. Wall switches are so easy to use my wife can do them without any instruction, so can the maid or house-sitter or anyone. Besides... the extra exercise in getting up to flip a switch is good for me... being too sedentary isn't good.
Apple Pay: whipping out a credit card is real easy... probably much easier than firing up some app on a phone or a little watch. I can also leave the card on the bill to be dealt with while I go hit the john in preparation for leaving the restaurant. Splitting the tab with friends is easy too.. we both plop our cards down and it's dealt with by the waiter.
Don't get me wrong... I have always been a friend of cool gadgets and technology. But we seem to have reached a point where stuff like this is really a matter of "solutions in search of a problem". None of this stuff is "needed" by anyone, and it's really a stretch to even suggest that any of it is even useful or time-saving.
I saw another big one this morning on the news. . .
Wearing a health tracking device to help you know your exercise levels will get you a discount on your health and life insurance policies. One company is so convinced of the benefits they are providing a cheap tracking band for their policy holders.