No chance to do what, Silverwing?
I have played a few games and from what I have seen, including my own experience, not every player lives in stagnation.
It screws up the team, for sure, I agree. But some people "move around the world" --- they change jobs or the reality of life changes, so they can't be where they wanted to be a year ago.
I can give you multiple examples from my own life.
So can you? Maybe? Or not.
Personally, I don't enjoy seeing top heroes quit, but then the new heroes get a chance to move up. Old die, young grow Cycle of life. Can be seen in any computer/mobile game (For almost 20 years now)