What does this even mean? sRGB primaries are chosen to maximize the gamut of a 3-primary additive computer display. They do not “correspond closely to retinal cell responses”.
I get that you're trying to be pedantic on this, and that's fine. But the fact that you're complaining about XYZ the way you are shows that... you've sorta missed a few steps. The pedantry goes much deeper, and XYZ is the way it is for some very good reasons.
RGB display primaries are only related to the CIE system insofar as people use the CIE system for characterizing and describing them. But it doesn’t constrain the choice of primaries. The primaries are chosen (more or less) to maximize the display gamut under the constraint that there will be 3 of them. They don’t match human cone cells per se (obviously there is some relationship between cone cell responses and maximizing the gamut, but it is not a simple one).
Which I took to be a complaint that XYZ doesn't represent cone response well.
And I responded that that's silly, because (1) XYZ wasn't designed to represent cone responses and (2) the bump is there deliberately to produce a more mathemetically orthogonal basis.
If you go back to all those books you've read over that decade you spent building your expertise, I'm sure you'll find the same info.
So I don't get your criticism. Poster above wanted a set of primaries that corresponds to how the cones react. The closest you can get to that is an RGB space like... sRGB.
Arguing about which design point (phosphor correspondence or cone correspondence) is "real" or "derived" is IMHO meaningless pedantry at this level.
The CIE color space isn't intended to represent the cone responses, though. The goal was to have a set of reasonably orthogonal, positive-definite functions with which to represent all visible colors as linear combinations of primitives. The "green" Y coordinate was chosen not for its color at all but because it matched the experimentally derived "brightness" function. X and Z are only kinda associated with red and blue.
But because CIE can represent all colors, you can use it to define other color spaces like sRGB which do correspond closely to retinal cell responses. There are also refined versions like LUV and LAB which are (sometimes nonlinear) transformations from XYZ and are intended to better represent perceptual "distance" linearly.
XYZ is just the basic language all these things are defined in, which was its purpose.