Pianoman
There's nothing wrong with giving examples of technical exercises. Pick one.
Take Hanon #1. After sitting with good posture, elbows at least as high as keyboard, forearms "floating" lightly at the keyboard, hand a mostly straight continuation of forearm line, fingers in natural slight curve: without rolling hand to left or right, nor holding it stiffly, keep fingers on the keys and pull down each key with a quick brief effort. By the time the finger reaches the key bed, all effort has ceased and the finger just played will pop up of its own accord by means of the key's back weight and the natural inclination of the finger to raise back to neutral position. Next finger the same.
Now, if you can do this with all fingers, evenly no louder than mezzo forte, with even sound, and make it a habit that is enduring and automatic, you've learned a good deal about playing with finger technique having isolated this correct basic mechanical requirement from other possible "bad" ways of producing sound.
Likewise, you could jog the wrist up and down with each key played and turn the hand and arm to the right and left when playing the fifth finger or thumb and make a nice robust sound bouncing your way up and down the keyboard and teaching yourself something that would fail utterly once you try and use this in music playing.
The list of nuances that can be done are endless, while the list of basic mechanics are quite finite.
And without the basic mechanics, the nuances are unattainable.
The reasons advanced teachers and pianists don't talk about mechanics are not because the subject is stupid and doesn't make sense or that things work differently for different people, it is, IMHO, because either they can't because they learned it and can do it but don't know how they do it and/or they would much rather talk about artistic issues.
In walking, we all do it basically the same, though one can be difficult and esoteric and say that no two people on the planet are the same and therefore don't walk the same and therefore each must devise his own basic mechanics -- which are different from everyone else's -- in order to learn to walk.
Really?
It is good that we learn to walk as toddlers by trial and error with guidance, help, instruction and example from parents, is it not?
If we all had to wait until say 10 years of age or later, no doubt there would be soooooo many books telling us all the different ways one must walk and the many "schools of walking": the gravity school, the toe school, the foot school, the momentum school.... and so forth... and many would be wrong and the result would be that orthopedic surgeons and physical therapists would be living in the golden age of medical careers.
There is a very, very, very narrow window of "how to play the piano" if your goal is to play classical piano the way it is meant to be played. And this starts with the finger and hand, using the smallest, quickest and most efficient muscle/movements to control the keyboard... period.
There are precious few ways to do this.
A handful, one might say.