“however, it's almost always good senior people working against the system to help juniors, not the system supporting any meaningful mentorship”

That’s how I often feel. I still get measured only by results so when I help somebody I am reducing my own output. I still mentor people a lot and involve them as much as possible because I feel it’s the right thing to do. My direct manager supports me but with one level up or more I feel that it hurts my ratings.

It’s also kind of annoying that all new interesting stuff goes to new people or interns and the most senior people are stuck with keeping things going and doing mainly maintenance work.