Part of macOS
ScreenTime…Screen Time
○ Leave it
Tracks app use for Screen Time.
What it is
Records how long you use apps and websites, if Screen Time is on.
If you stop it
macOS starts it again straight away. Leave it.
The verdict
○ Leave it. Part of macOS, or something that starts again by itself. You never need to close these.
In Activity Monitor
ScreenTime…UsageTrackingAgent…
… means any name that starts this way.
From Procession’s guide, in the words the app shows.