cymk is a hoax perpetuated by the printing industry to get you to buy more ink
Why does this make so much sense
Because printer manufacturers program their printers to put a little cyan in with the black to make black look more "vibrant" on the page. It's just a bulshit way to make you run out of ink faster
That's a problem with the way printers utilize colors, not the model itself. Subtractive color is the best model for printing on paper.