I often want to measure a period in seconds, not minutes or hours.
It makes calculations easier.
For instance, the “Change tempo” effect uses seconds.
But I need the exact time, to the ms.
The selection toolbar only gives “seconds”, integers.
I want “seconds + milliseconds”.
Now to find that I have to first use “seconds” then switch to "hh:mm:ss + milliseconds " to work out the exact time.
Or do a lot of multiplying by 60 and 3600 and additions on a scrap of paper.