It’s all subjective of course. New teachers will join, some students will like them, some won’t. If a teacher is charismatic with great interpersonal skills, I have noticed that this seems to be enough to make them popular for many students. Which is fine, because different people want different things from the platform.
However, if a teacher’s skills are outstanding and a student has stuck with them for years, reaping the benefits of their class, for that student, that teacher is irreplaceable and whoever comes along later to take the class will disappoint.