Yes it’s just as much if not more on the student when it comes to improvement and not all students mesh with all coaches, it has a lot more to do with skills of teaching than popularity, but wouldn’t success also lead to instructors being popular?
As is nearly everything you post
So all the positive reviews on instructors pages on skillest, the repeat customers that many instructors have and all the data available that is used to help students isn’t proof that we know about teaching and making people better. And for learning the better instructors can figure out how to get the student to learn.
but again it’s on the student to take the knowledge they gained to get better. Application isn’t easy other wise we would all be great golfers.