Color perception in the eye is no way linear, it is not even RGB. In reality, the three types of receptors work on something like "3 somewhat overlapping, wiggly, asymetric bell curves" of which one is roughly some kind of blue (S), one is a kind of green (M),and one os some greenish-yellow (L).
The brain transforms this information into what you see as "colors" (including red, green, and blue), but there is no simple (linear, logarithmic, or similar) mapping corresponding to perception.
What's of practical interest is what your brain thinks is the correct color in a typical situation, and what you can represent well on a computer (preferrably having the hardware do any necessary transforms). sRGB works well for "monitor in somewhat dim room", and that is why you want to use it.