“Ambition” covers too many human drives to be traced to such a narrow cause.
Sure, someone could be so driven to escape their disempowered or miserable situation that they form an ambition to do whatever’s necessary to rise above them, or to turn the tables on their oppressors. Or they may have grown up in an environment where high achievement was the key to parental approval, so that ambition became a learned habit.
Ambition can have more positive causes, too: in order to effectuate substantial change in the world, it helps a lot to acquire power, resources and the support of others. That can be an altruistic form of ambition, one driven by a desire to make the world a better place.