ummm… yeah i know.
primary colors are from subtractive mixing, ie mixing paint… like i said.
and it originated from back when they couldn’t make a good cyan or magenta, so the color wheel had blue and red instead.
you’re supposed to be able to mix the primary colors to get any other color, but that’s bullshit unless you want it to look like a medieval painting.
additive color came a few centuries later with electricity and artificial lighting and is not relevant.