A manager decides to spend their energy managing their relationships up, down or sideways. The very worst will focus solely on managing the upwards relationship, but that's precisely what makes them hard to dislodge: Every second of their day is spent on efforts that helped their job security by relationship building.
So it's not just that the best manager is also the best at finding a new job, but that every second they spend improving their org's performance is a second they don't spend trying to fool a typically not-so-good middle manager into thinking they are indispensable.
This is also why, every time I've seen manager culls, I have found that it was rare for upper management's idea of who was easier to replace was to match that of peers and reports. The ability of the bad manager to hide the truth from the exec is much stronger than people realize.
This is true. I've also found that there are perverse incentives when it comes to (especially upper) management. Building up enough political clout in your organization that aren't answerable to many people, and managing your image among the few you are answerable to, is the best skill one can have if the outcome is steady long term employment. Providing value to your company and coworkers doesn't correlate as much with surviving corporate haircuts like these.
Their upper managers don't want "best", they want loyal, they want yes men that will make perfect henchmen, that's what best is for them so they get exactly what they're looking for. People who rock the boat aren't gonna cut it.
So it's not just that the best manager is also the best at finding a new job, but that every second they spend improving their org's performance is a second they don't spend trying to fool a typically not-so-good middle manager into thinking they are indispensable.
This is also why, every time I've seen manager culls, I have found that it was rare for upper management's idea of who was easier to replace was to match that of peers and reports. The ability of the bad manager to hide the truth from the exec is much stronger than people realize.