Those were F keys before, which I could put my finger on and use without having to hunt for the correct featureless spot on the Touch Bar every time I needed to step.

> It's not completely useless for programming: for example, I use the button to stop an app in the debugger pretty often.

The hypothetical advantages of that usecase are negated by the lack of physical F-keys, which are critical to start/stop/step through code.