Android Pie's Adaptive Battery management gives more information on battery life and notifications activity
Can be seen from the screenshots that battery and app performance monitoring is a lot better on Android Pie.
The notifications management per app is also improved so that you can now not only see which apps most recently sent notifications, but also sort the apps by the total count of notifications, and then you can fine tune within each app what activities will trigger notifications or not (notifications wake the phone up every time so they can contribute to draining the battery).