For a cinema feature, the audience will indeed have a DCI-P3 calibrated display, but that's pretty much the only use-case. It's also an easy pipeline: capture in RGB, process in RGB, proof in RGB, reproduce in RGB. Even then, variations in exhibition equipment mean it's back to "pretty much the same colour", but at least you started at an agreed standard,
For any kind of print work, though, I absolutely agree: so much changes at each stage, and even across a print run, that you're really only going to get "same colour within reason". The switch from additive (RGB) to subtractive (CMYK) colour spaces means there's no substitute for proofs. (I used to do a small amount of print design... I'm glad I don't do it anymore)
Biting the hand that feeds IT
