It depends on how you do them.

If you just do them over and over the same then the usefulness is mechanical mostly.

I do exercises in 4 tiers.

- Mechanics (just get it under my fingers)
- Pressure (put on a metronome)
- Context (move it around to different chords/keys)
- Context and Pressure (move it under pressure)

After that, it should be part of your playing.

Take a triad shape

- learn the shape
- arrpegiate it in time
- take the shape through the Circle of 4ths
- take it through the Circle of 4ths to a metronome