A calculator is a tool that replaced the slide-rule or Abacus - no one contended the Abacus replaced teaching or teachers. Ditto an iPad which is effectively just a fancy calculator in this context.

Similarly Youtube didn't replace teachers - it afforded remote learning and correspondence courses a new medium for transmission, recording, and playback of teaching.

More to the point none of those were trained on a corpus containing the history of human pedagogy, were capable of inference, or of generating dynamic learning resources based on best-practice models with inherent self-correction and pedagogical reinforcement mechanisms.