Like the prisoner's dilemma where everyone gets a worse outcome than if they both cooperated.
The arms race of exam grades is a clear example: because everyone wants to maximize their marks, grade thresholds go up, hobbies go down, joy of living goes down, stress goes up, and the function of learning is gone.
Though like a Nash equilibrium, it kind has to be that way. Because there aren't alternatives. Not a moral failure, just an optimizer.
Where everyone is helped to get good grades in the name of "equality". But still people want grades to have value. Thus everyone has to work harder to achieve university spots each year. (It has to be limited by design, otherwise with free choice the point of grades wold be lost!)