By uninstalling Instagram that I was addicted to and my statistics would crazy shift, saying you spent less time than I actually did.
I wanted the simpler approach that would better answer the question: "how long was my screen on and unlocked today?", so I built a small Android app that just measures that and shows it as a floating overlay or in a widget, plus a lot of customization to it.
No network calls, Private, Free and Open Source, Ad-free. MIT.
Perhaps some manufactures are handling digital wellbeing differently, but that problem that I needed to solve existed and still exists on my Xiaomi device.