In my opinion, the matter is more complex. I will try to argue my opinion sincerely and openly (I hope also clearly). First of all, I believe that each of us can be teacher and student at the same time. I will spare you an in-depth discussion of this concept.
A Conservatory Diploma and "exams" should not be understood as a destination, but as a starting point. However, they are tests, goals, etc., that force us to glimpse a milestone and overcome a step. It may be true that taking exams does not always lead to growth, just as it may be true that they can instead be a panacea. The before, during, and after the Diploma is governed by our willingness to listen to and adopt the experiences and knowledge of other musicians. In my modest musical life and as an "occasional teacher," I have encountered various types of students or other musicians who have asked me for a technical-musical opinion (this being when I found myself in the position of teacher and not student).
Some surrender themselves for a period to teaching and take as their only path what the teacher suggests, or rather, what the teacher suggests not to do. Some, with "their own timing," make more or less "their own" certain notions and internalize them. Others may struggle a bit to communicate and therefore to deeply learn the teacher's suggestions. Others, of undoubted intelligence and ability, listen, filter, select the "information," and either consciously or unconsciously conclude that, ultimately, what they think is more correct. In short, between a clear division of those who can have Teachers and those who do not and have never had Teachers, there is also a type of Musician who, with humility, looks around.
As a student, in my youth, I encountered several Teachers who said things that were "not in my wheelhouse," but later, I had to realize that... "my strings" were still too few and... too short to be able to vibrate in resonance with those concepts.
Therefore, beyond the fact that the discussion should be deepened, developed, and debated, I quote Fabio's phrase: "It would be nice to find a good teacher again...". I also invite you to reread Horowitz's thought, posted by Frank. I like it very much.
P.S. For painting and drawing (perhaps less so for the latter), the matter is different. I can find myself in front of a landscape and "interpret it," in short, with two or three splashes of color. And this can be judged as whimsical, personal, and excellent in "free interpretation." In the performance of a Chopin ballad or a Paganini capriccio, however, one must respect certain rules, even if flexible, and certain skills that allow for a good representation of the work.