I remember reading that among the studies that compared student evaluations of their teachers with student learning, only one study was really scientific, in that it 1) measured learning by an external, independent test (not by the grade), 2) was longitudinal, i.e. tested students *before * they took the course as well as after, and 3) also measured student performance in later courses, for which the given course was a prerequisite. There was a slight negative correlation between student performance measured this way, and student evaluation of the teacher. In other words, hard work is arduous, but it pays off. I believe there is far too much emphasis on positive student evaluations.
EDITEDIT:
@CuriousFindings suggested I add references. I am not sure if any of these 3 is the article I was trying to remember, but they all seem highly relevant: (Work in progress)
https://www.tandfonline.com/doi/full/10.1080/01973533.2020.1756817