Anecdotal stories are just that, though.
One of the best teachers I had, and one who partially served as an inspiration for me to get into teaching in the first place, stepped well outside his normal maths/science/IT brief, and would introduce philosophical concepts to us. He'd mix in questions about how large the universe was in amongst testing us on times tables and square roots. (was a senior primary school teacher)
Depending on how conservative the audience was, some of the challenges he was throwing at us were outside the brief of his teaching, and could be challenging what parents were teaching. But that's part of the raison d'etre for some of the best teachers I've met, whether that is their professional position or not.
Likewise, I had a fantastic language teacher, and she was very much the opposite. The reason she was so good for me wasn't because she was trying to 'expand my mind' in any holistic sense. It was because she set high expectations, demanded my best, was supportive, and pushed me to a position of focus.
Both were super teachers.