In a comments sub-thread, I noted that by definition, GE is adding variation in fitness to the population. Even if the initial population starts out perfect or uniform, it won’t stay that way for long. Sooner or later the difference between the most and least fit in the population will become large enough for selective pressures to act. There will minimally be purifying selection, removing the least fit, and increasing the average fitness back towards some equilibrium state (assuming a stable environment).
Genetic Entropy is a self-solving problem.