As you say, “higher usage shows better”. I think that’s the core thrust of the Usage GUI. If you can’t see it, it’s much less significant and so perhaps shouldn’t draw your attention.
The Day Usage in the view you have is showing integrated power per hour. Meaning the sum of all the watts for that hour for that device vs your Mains. If you view the Flood Light device in the Device>Usage view it will be re-scaled without reference to the Mains so the trend in Usage will be visible there.
You can also look at a Power Meter view (Day/Week/Month) for the device and then expand the vertical axis so the waveform fills it over that time period. Any trends (the Daily ones especially) should pop right out in much greater detail than available in the Usage interface.
If they are really low frequency device events, you can add them to alerts or the timeline… Or if you really want accuracy you can use data export to look at hourly or daily trendines.