A lot of power users look at their keyboards. Touch typists are a very small minority, even among power users. At least pure touch typists (people who only touch type).

And these computers are not purely for power users.

I wonder how many folks touch-type with the function keys. I touch-type, but I still need to look down to use the function keys.

I used to be able to touch type the speaker volume and mute F keys. With the slider or volume mute buttons, I often have a hard time hitting them correctly on the Touch Bar. This is after having it for years.

If they're grouped in blocks of 4 it's reasonably doable, especially for the ones at the edges of the blocks (for example F4 and F5 are popular buttons for IDEs and even browsers or other common applications).