For photoshop, which I'll admit I use infrequently, it's very handy.

I also use Ableton and Lightroom a reasonable amount (neither are my day job though), and am constantly left wishing that they integrated with the touchbar. I have a midi controller that I use for sliding controls in both when at my desk, but I don't take it when I'm out and about, which is where having the ability to adjust analog controls (sliders/dials) with the touchbar would be incredibly useful.