Was that the first/only moment you had a draining/bad student? Seems quick to give up because of one bad experience, maybe this was repeating?
Personally, I felt similarly once the people I'm mentoring started using CC and Codex and similar stuff, as a lot of the questions they asked me were easily answerable by the agent, so I guess I had a brief moment of "But what value do I even provide in the world anymore?".
I ended up kind of restructuring what I'm trying to teach, and instead of getting them more exposed to the mechanics of software engineering, I've started leaning more towards the soft skills like how to collaborate, how to get a feel for when things are right/wrong, how to understand better/faster, and similar things, all still related to software engineering of course, but I basically try to ask myself what I can teach them that no agent/model could, and do that stuff.
I even started introducing mentees to each other (not sure why I didn't before but alas), and have them collaborate on projects together, and figure out what works/not in collaborations with others, as no model can teach you that, as just another example. It's surfacing a whole new host of issues to work through, so seems to work fine :)