That documenting is self-fulfilling. It creates a bias. That is, the manager is biased towards fleshing that out, not signs of hope and change. The manager is also biased to covering their own arse, not giving the employee a fair shake.

Yes, there are cases where the employee needs to go. But there are others where that's not exactly true.

All that said, it's a relationship. Life is too short for unhealthy and unproductive relationships. When I find nyself in such situations I update my CV and start looking to move on. Somethings are what they are and not worth the fight.