Thing is putting the horrific privacy concerns aside it’s not like it’s a bad idea from a health perspective. Everybody being simply more aware of the things their body is doing is immensely helpful on a societal scale.
Problem is there aren’t any devices that are local only or otherwise truly private. Apple stores your data locally on your phone which is good, but there’s no guarantee it’ll always be that way.
Pass a law that protects wearable health data under HIPAA and I’d consider it.