I always understood that a person being competent in role A is being promoted because of being good paired with maybe personal or/and corporate development goal

I always understood that a person being competent in role A is being promoted because of being good paired with maybe personal or/and corporate development goals. Once in the new role, with likely higher pay, it is very unlikely to go back. Instead of going back the person will try to stay afloat in the new role. Some will rise to the challenge others not.