You're in a metabolic phase where you are craving junk food. Let me shove your favorite things in your face in constant interruptions of your media consumption because you quit buying my product and you're vulnerable.
I'm an imbecile managing healthcare insurance. Your resting heart rate is well below average because you've been an athlete in the past. I'm too stupid to handle this kind of data on a case by case level. You have absolutely no other health factors, but I'm going to double the rates of any outliers because I'm only concerned with maximizing profitability.
The human cognitive scope is tiny. Your data is a means of manipulation. Anyone owning such data can absolutely influence and control you in an increasingly digital world.
This is your fundamental autonomy and right to citizenship instead of serfdom. Allowing anyone to own any part of you is stepping back to the middle ages. It will have massive impacts long term for your children's children if you do not care.
Once upon a time there were Greek citizens, but they lost those rights to authoritarianism. Once upon a time there were Roman citizens, but they lost those rights to authoritarians, which lead to the medieval era of serfs and feudalism. This right of autonomy is a cornerstone of citizenship. Failure to realize the import of this issue is making us the generation that destroyed an era. It is subtle change at first, but when those rights are eroded, they never come back without paying the blood of revolutions.