There are actually five primaries, they normally go by the abbreviation CMYK i.e. Cyan, Magenta, Yellow, and Key (which is Black & White). These truly make every color its the reason they have been used in color printers since color printing was a thing.
Primary color systems are a can of worms. Which is best actually depends an a bunch of "if/then" procedural questions about the project and media in question.
CMY functions on how transparent colors filter one another when overlayed. Printers favor CMYK* because the inks used are transparent. CMY tries to work upward from a platonic ideal of colored light. It capitalizes on the fact that transparent inks/paints are less subtractive than opaque ones (duh) to try to make a system that functions a little closer in the abstract to what you'd get with pure light (where colors are additive: mixing makes them brighter instead of darker). This doesn't mean it gets more accurate end results, it just means the process of getting those accurate results can borrow some ideas/math more directly from our understanding of light. This makes it more predictable in an abstract absolute sense (essential for a professional printer)... but also causes it to break down the less transparent (i.e. more subtractive) your colors are.
Opaque paints are purely reflective, and thus absolutely subtractive: their color behavior does not really follow pure light models. This is why RGB was developed and used for millennia before CMY, and continues to be used after. It's not accurate to the physics of light, but it's not trying to be: it's meant to model the behavior of subtractive pigments, not pure light. It sidesteps the problems CMYK runs into when trying to combine purely subtractive color.
If you want to get mathematically pure about light all by itself, neither is an accurate model. Both are to some degree attempts to pour alphabet soup into a typesetter's drawer. There's a minimum of around 1/6 of the visible spectrum that cannot be reproduced by
any given 3-primary system, and which colors are outside the gamut change depending on what 3 colors your system uses. This gets "fun" (read: cursed) when you're talking about digital art, digital photography, and print reproduction of traditional art (all of which are restricted to 3-color gamuts).
So broadly speaking: CMYK for transparent color, RGB for opaque color. CMY if you're layering transparent on top of opaques. Glazes made from reduced opaques can go either way, not depending on the colors, but depending on the surface optics of the pigment particles (thinned opaque is not physically the same as transparent). So keep a scratch surface handy as you paint, and prototype/test your glaze or transparent mixes
on your underlying colors there first.
And remember: perfect color reproduction is for printers and monitor calibration. You are a painter: you pick the colors for other people to worry about reproducing.
*CMY is the primary color system. CMYK is the printing color system. The difference is in whether or not you're spending money on ink. CMY is still subtractive in practice, so in printing it's cheaper to use black ink to darken rather than layer on thicker color, but if you're only talking color in abstract then you can layer away.