I agree and think this applies not only to playing the piano but to life. Even if you try to run away from, ignore, suppress or deny your feelings, they are still there. They will still affect you, and forcing it down (or into the dark as you say) often makes it worse.
I think you need to work consciously on technique. Realizing that worrying about things, or stress in general can affect your technique is a part of that. But I made progress with those things by accepting this rather than fighting it.
I hope I understood you correctly. Do you have some examples from your own experiences that could explain your point of view a bit deeper?
eg when play sixths and thirds in the rh. I find those a bit uncomfortable at times. melodies in sixths and thirds.
I also play the (piano)accordion and it is done more on the accordion than the piano even if I do it on the piano.
I had a teacher who told me to play exercices from a book by Czerny-Germer I think.
Just play was the ideal as I remember it. I have even had people tell me to just sing. It did at specific moments help me sing above high C but I still had technique issues. I might have used certain bad habits.
Piano teacher teach technique and not psychology. My current singing teacher speak a lot on psychological issues and my piano teacher to some extent.
I think this issue is a lot about having issues with feeling your body and all its movements.
I miss a lot of fundamental stuff I guess. Sometimes I think too much about the details.
A lot of teachers can miss some of the issues students have with the fundamentals, I think. This is easy when they often teach by using a certain method rather than trying to meet the student. This obviously requiere a student feel safe at the piano. It is often: the students should meet the teacher instead of the other way around. The teacher need to meet the student where he/she is rather than asking the student to meet the teacher where he/she is.
Students are asked to be very adult like and it might work for adult sometimes but not for kids.