Exactly, my best "professors" were not, technically "professors".. a few were basically grad students, but the best were paid instructors who came from industry to teach. I'm sure perversely they were also the worst paid & treated.
I learned more from that “professor” than most of the rest.
One in particular said straight up on the first day, “I do not like teaching. I am required to do this in order to do the research I want to do.”
I guess I at least appreciated his candor, it gave me insight to what many of the other professors felt but never said out loud.
…and actually he was in the better half of instructors (there was an admittedly low bar with a few excellent standouts).