@hilde45 how do you explain the grandmother that doesn't necessarily use science, only experience and intuition to cook a glorious tasting meal.
A recipe is a scientific thing and so is apprenticeship (in person with another person); so is daily trial and error. None of it is guesswork, which seems to be what you're suggesting the grandmother does. Just because there aren't formal measurements or numbers doesn't mean there isn't systematic attention paid to quantities, ratios, timing, and technique. A lot of the audio suggestions flying around lack any of those things with any systematicity.
And finally, acoustics and hearing are fairly precise things. It's harder to get the image and tonality of a singer correct to the ear than make a lasagna taste decent.