We need both humans and AI. But there are problems with both, so that's why they can hopefully complement each other. Humans might have limited patience, availability, etc. and AI lacks empathy, and can be over-confident.
> Why are we doing this to academia when the better approach would be giving TAs better training in actual teaching?
Sure, that is a fantastic idea and some researchers have explored it.
But, what's wrong with doing exploratory research, in a real-world deployment? In the paper we describe both where CodeAid failed and where students and educators found it useful, in a very honest way.