What is the difference between RGB and RYB color models and what are the implications?

As long as Wikipedia is alive you can read into my conclusions

Color Mixing

Additive Color

Complementary Colors

Substractive Color

RGB Additive Color Model

RYB Substractive Color Model

Complementary Color Afterimages

So far RGB Additive Model is more "modern" analytically ... the next link shows it has more backing in the CIE Standard Observer

CIE Standard Observer

Consider the following.

Negative Afterimages

The implication is that no tri-chromatic additive system can be used as a model for how the eye is stimulated, perhaps a spectral system of rod and cone responses will come into use.

While RGB is more prevalent, RYB has co-existed. To reproduce an RYB image the way an RYB image was produced, RYB is neccesary. In some tri-chromatic primary pigment systems RYB cannot be reproduced with other pigments. Appearance of an image depends on lighting and other factors described by CIECAM below.

Pantone's Hexachrome 6 color printing utilizes more than 4 colors, and while isn't the full spectrum of wavelengths, it is more than twice as much as tri-chromatic. Kodak has the HIFI color model and many inkjet printers use a model with more than three primary colors.

Pantone's Hexahrome Color Model

Consider the full spectrum of wavelengths.

LMS

And if that isn't cumbersome, there is the whole expression versus perception dilemna, such as inter-image in preferred photographic "look and feel" that can frustrate composition completely. Consumers like greener grass and bluer skies. Portrait customers have flesh preferences. Image to image, inter-image, can have a psychological effect on perception.

Composition

There is something to be said considering workflow for "good enough color"