I see potential. I can also estimate it and quantify it and can explicitly evaluate it. Is that good? It is sometimes painful. I have heard many many singers. I can hear their strengths and their weaknesses. Excluding everything but sound, I do hear if musicianship is weak. What is musicianship? It is a range of skill and may include knowledge and nomenclature, but is demonstrated in singing. The subject of music theory has something to do with that, but not in a creative fashion. When I hear a singer, I know what needs some help or attention.
I was cursed with a thing called perfect pitch. It is hard to describe what that is like but it is like being able to differentiate color in a painting or timbre of a specific instrument as compared to another but is more subtle. Nonetheless, one pitch compared to another has some characteristic of being able to hear and recognize, as you recognize someone's voice. How helpful is this? I also hear chords, the inversions, the voicings, instantly and without "analyzing". I just get the whole "picture" all at once. This is also useful for singers, for me to have this broad perspective.
I write music EVERY day and have over 2000 pieces: songs, instrumental, jazz, orchestra, big band, marching band, country, pop, R&B, Ballads, Latin, Broadway, etc. 26 styles total. What other vocal coach/musician/teacher can say that?
One could say that specialization is the key. Is it? Diversity is the universal key or solvent. Da Vinci was in many ways similar to me, in that I also know architecture, engineering, building methods, and several sciences in depth, including acoustics. I draw and have painted and this "cross-training" has added to, rather than taken away from my music.
Despite the knowledge of music and the skill of a singer, I must say that the single biggest issue or struggle singers have, has nothing to do with singing or music. The single biggest issue always will be the mind of the singer and the state of health of that mind. When it is healthy, the mind can learn rapidly and pass it on to the voice. More careers are made or broken in the mind than anywhere else. Singers who spend time criticizing themselves or others will find that is the most deleterious activity there is. Energy will be used to build up, to tear down, or to maintain and it is nothing more or less than a mere decision, a choice.