Today as an adult, I just see an ethical issue with letters of recommendation. By asking a teacher to write a letter of recommendation, you are asking them to recommend you based on what they have seen and observed of you while you were sitting in their classroom. I consider public education to be a walled garden, in other words, what happens at school stays at school from the paid professional point of view. I don’t consider it ethical that someone in a supervisory position, who is paid to teach every student that walks in the classroom door, who issues grades and knows confidential information about many students, ethically can submit to a 3rd party details about their experience with the student.
That’s my perspective.