Okay, let's try an example.
Suppose you see a person wearing a black silk jacket with an embroidered dinosaur on it. That person is lavishing admiration on a 1965 whitish Pontiac. You are struck by the combination of the rich tones of the car and the jacket but the thing that ties it all together is the barely visible dinosaur on the jacket. You react intuitively to the subject and want to photograph it.

Do you know what to do to maintain the full detail in both the white car and the black jacket? You might figure to meter on both and take the average, you might figure something else. The averaging method could quite easily make both subjects reproduce poorly. Without knowing the light meter readings we can't say.

However we can say that if you are using a calibrated system and are up-to-speed on the Zone System, then the decision making process is in your hands and not at the behest of an automated system. A subject such as the one described is easy to handle. After you are well versed in the procedures, the amount of time it takes is really only a matter of a few seconds. It might take several years to get that good with the system, but photography has no equal to the Zone System for versatility and expressiveness (*).

The Zone System is excellent for the person who has no fear of technical issues and a commitment to making the best possible photographs. And as a language, it presently becomes a natural element of the way you think and perceive.

Some will figure that digital photography offers as much expressiveness and versatility as the Zone System. I think there is room for discussion and debate about that point.