Yes the touchbar slider is heinously bad. If my memory serves, you have to first tap one area to get a slider to appear and then slide that. <facepalm>
I got the Air instead of the Pro basically for the hardware brightness / volume keys and lack of Touch Bar. It’s such a relief to use these keys without taking eyes off the screen and to not accidentally tap something on the Touch Bar that breaks flow.
By the way, I think you can edit the Touch Bar to replace the volume slider with volume mute/down/up “buttons” instead of the slider which makes it a little better.
As a hater of hidden UI like Apple has been obsessed with for several years (force touch, most of the touchbar, edge swiping (as convenient as it can be sometimes), etc): there is a way, but why would you ever try it:
Touch-and-drag on the volume buttons to immediately drop into a volume slider, relative to where your finger started.
It's a pretty nice interaction, honestly - better in most ways than the buttons alone I think, in part because you can be both more precise and make large changes faster. It's one of the VERY few places where I think the touchbar does something positive[1]. But the vast majority of people who would like to use it have no idea it exists.
[1]: ... except when the touchbar freezes while doing this, and continually sets "max volume! MAX VOLUME! MAAAX VOOOLLLUUUUUUUMMEEE!!!!" several times per second until you do a hard shutdown to stop it from blaring [whatever you were listening to] at you because it's also stealing focus from whatever's on screen so you can't even click the "yes please shut down" button. Then I'm somewhat less fond of it.
You can also quickly swipe over the volume button in either direction to increase/decrease the volume, works for brightness as well.
Personally I don't have a terrible aversion to the touchbar, but my biggest gripe is that my right hand naturally rests in a position that randomly presses the mute button.
I got the Air instead of the Pro basically for the hardware brightness / volume keys and lack of Touch Bar. It’s such a relief to use these keys without taking eyes off the screen and to not accidentally tap something on the Touch Bar that breaks flow.
By the way, I think you can edit the Touch Bar to replace the volume slider with volume mute/down/up “buttons” instead of the slider which makes it a little better.