Yeah, most people I know almost never use F keys (except perhaps F1 for help). They leave it on the media-keys mode... which is the same as the touchbar's default values, but without needing to know what mode it's in.
With the physical media keys, if they want to mute, it's always the same button. Pause music, always the same button. They're great in a way that the touchbar completely destroys.
(and yes, I know you can change this setting, but if we're assuming non-techy-users we also generally have to assume default settings.)
Honestly, I hardly ever used the function keys either. As a result the Touch Bar doesn't really bother me -- but neither does it seem the slightest bit useful for the most part.
I just hated the lack of ESC key (which they brought back, though my Mac is older). I have no muscle memory for any other key in that row.