It's the complete opposite for me. I enjoy the process of mentoring juniors and am usually sought out for a lot of little issues like fixing git workflows or questions on how a process works. Working with an LLM is absolutely not what I want to do because I'd much rather mentees actually learn and ask me less and less questions. My experience with AI so far is that it never learns at all and it has never felt to me like a human. It pretends to be contrite and apologises for mistakes but it makes those mistakes anyway. It's the worst kind of junior who repeats the same mistake multiple times and doesn't bother committing those to memory.
You're right, I'm probably lumping the first group over-broadly, since I understand them less well.
It would make sense for there to be subgroups within the first group. It sounds like you prioritize results (mentee growth, possibly toward long-term contribution), and it's also likely that some people just enjoy the process of mentoring.