Think about that super watch that even tracks your body temperature.
Do we need that?
I would say that it is pure marketing.
In my many years of experience, I see the reverse that people get tracking devices, and after a while, they feel trapped, their motivation goes down the hill.
Those devices also can cause a lot of guilt on people and make exercise be a boring mechanic thing.
A good example here is the 10 thousand steps trackers.
I have seen people miss one day of their "targets" and then guilt comes in, then the main result after a few days is that they can stop exercising altogether.
If you find someone that uses those trackers for more than a month, it will be a miracle.
So please save your money, do exercise because it is pleasurable because it is fun.
When the fun is out, it is time to sell that excellent watch on eBay.
Year after year I see people buying new toys.