Comment by wwweston

No. So much no.

It utterly destroys the “quick incremental adjustment” that taps are better for. It makes it more involved to even complete maximal adjustments, which are just press and hold. It makes all adjustments more involved, it’s not merely a matter of locating a physical key, it’s orchestrating movements your eyes and hands have to track together toward a location that can’t be known , through touch detection that can get fussy for any number of reasons.

This is not theoretical. This was my experience with a touchbar MBP. The idea was just wrong for this kind of routine function.

Meanwhile, I can adjust volume blind by feel on a MPB with function keys. I never for a moment when doing this for audio or brightness think “I wish I had a slider” and even if I did I know how to find one for use with the touch interface every MBP ever has had.