> what I see is that such people shift away from teaching/mentoring as it takes time/effort that their manager does not reward

I don’t think it’s that simple. I work with tons of talented engineers who put a huge amount of effort into tasks that management doesn’t care about - like refactoring our codebase.

In contrast everywhere I have worked management has cared about being able to level up new developers and under performers (assuming it’s a skill deficit).