RGB curves - Why does adjusting the G curve also result in a change in R and B channels?

[Stampede]

@ggbutcher

Now, when an image is captured by a camera, it’s done so on a sensor that has a specific spectral response. This information is captured in the camera profile, which might reside in a humungous table in the raw converter software, or in a separate profile.

Is this what the DCP profile does in RawTherapee in the color management settings?