> They can and do already track your app usage (you can see this if you check your usage history on the Google data dashboards).

Is my Android data usage by app stored somewhere online by default? I thought the stats are only kept locally at the OS level, and are not connected to my Google Account.

In any case, "Digital well-being" seems to be about tracking screen time, not data usage. And as far as I understand, it sends that data back to Google.

Sign into your google store account on another device with a web browser, it gives you full information about what apps you have installed, how long you have used them, and even the ability to install apps remotely (!).

This is a normal functionality of every app store: keeping track of what and when was installed.

But as far as I am aware, Google Play doesn't collect data about the actual usage of each app in terms of screen time.

That's where "Digital well-being" fills the gap for Google.