Is ambition fueled by trauma and failure?

It certainly can be, depends on what that ambition is. The only ambition you should have is to be happy, healthy and surrounded by those you love. If there are other ambitions you need to analyze where thery are coming from. Odds are they are not actually your ambitions.

“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.

Quite the opposite. Ambition is the natural state of humanity. We are always looking to the next goal, and seeking self-improvement. Some just dream bigger than others.

I would wonder if Bruce Wayne would have not become Batman if his parents would not have walked home through crime alley? Or Peter Parker took out the thug who ended up killing his Uncle Ben?