At the bottom of that page there are links to more information.

https://www.apple.com/privacy/approach-to-privacy/

> Your iOS device can collect analytics about your iOS device and any paired Apple Watch and send it to Apple for analysis. The collected information does not identify you personally and can be sent to Apple only with your explicit consent.

You have to opt in to analytics collection when you set up the device and in Settings>Privacy>Analytics>Analytics Data you can examine or download everything which has been sent to Apple.

If you take Apple at their word that they're only collecting what they say they are, they're not bad.