Teaching is an essential part of scholarship. My late friend and colleague, Vic Elias, put it this way: "You teach this stuff long enough, you learn how to use it." The 1981 Nobel Laureate for Chemistry, Roald Hoffman, similarly said "[I]t is through teaching that [young academics] become better researchers." It is also true that the teaching part of a professor's career, which nominally makes up only 40% of the workload, is expected to have by far and away the greatest direct and leveraged effect on society and civilization. Teaching makes us human.
But research informs teaching, too. The first and most obvious way is in constructing syllabi and the programs they shape: research tells us what to teach, and why. This changes continually as knowledge advances. This has changed radically with the introduction of the web, wide social networks, online tools including videos, and will change even more radically as AI tools take hold. Yet a second way, a possibly more important way, that a human researcher/instructor influences teaching is that a researcher is an excited learner, and can share the electricity of being on the border of the unknown.
Research also tells us (if we're listening) how to teach, and how students learn. The pedagogical literature is unequivocal: engaged, active learning is a critical component in deep, integrated learning. The student must do, to understand. The addition of radical new tools has not changed that, so far.
Finally, teaching as we know it today is a human activity. Besides having something to teach, and knowing how to teach it, the professor must be a social person, able to show warmth, strength, and confidence, as needed. Goethe in a letter to one of his teachers said "instruction does much, but encouragement does more." Learning how to encourage students in an age of vast distraction still seems like something to aspire to.