Why is Device Identifier collected as Data Linked to You for some Apple apps but not others?

Whether the device ID is linked to you or not linked to you depends on the nature of the ID and whether Apple can link it to user identity. If it can be linked to your identity we have listed it as Data Linked to You, and if it cannot be linked to your identity, then it is listed as Data Not Linked to you. For example, Contacts shares a device identifier with Apple, but it is not linked to your identity, so Device Identifier is listed as Data Not Linked to You.

https://support.apple.com/en-us/102399

Here is a screenshot of the data this app tracks based on the nutritional label from the app store:

As a comparison, here is the nutrition label for Apple's own Contacts app