Even though the "basic" telemetry data is quite the list [0], I agree that it's not nearly as intrusive as the "full" set.
> only when you have it set to Full level
"you" (probably any users) won't set the level to "full"; this is the default setting (source [1]). MS only offers "basic" as opt-out (which it really is not).
I skimmed the list and these particular ones jumped out at me:
> Movies > URL for a specific two-second chunk of content if there is an error
> Music & TV > Service URL for song being downloaded from the music service -- collected when an error occurs to facilitate restoration of service
> Photos App > File source data -- local, SD card, network device, and OneDrive