This seems to me the wrong mentality. What you ultimately care about is the leverage you have over the entity holding your data. In most cases you have more leverage over the state via voting and lobbying.
> it's probably more a concern about anyone having too much data
I agree. The issue is what you give up when you let people have that data, and how to mitigate those downsides.
> I don't mind different organisations having little bits
Sure, but realistically that's not how it will work. The point of gathering all the health data is that it's valuable to provide your health information to other businesses. This is specifically called out in the article, with the example about the gym and your doctor.
> but I get concerned when people want to bring it all together.
Bringing it all together is the whole idea. Apple may not literally give the raw data to anyone, but they will do what is functionally equivalent. They'll provide an API for third parties to make business decisions about your individual health. There is no way to do this is a privacy-preserving way.
