It's a touchscreen instead of physical buttons. People had the same concerns about the iPhone screen replacing the hardware keypad on smartphones. In that instance, the improved flexibility of the touchscreen was more than enough to compensate for the reduced affordances. We'll see about the Touchbar. I like it a lot--for example, having the mute button persistently handy (and obvious) during web conferences.

Touchbar affordances are better than the iPhone in that the persistent touch buttons are immediately above hardware buttons. My mute button is directly above the + key. My volume control is directly above the - key. My brightness control is directly above the 0 key. I can get a finger there without looking and immediately adjust by sliding left or right.