In organizations, everyone's existence and position is politically supported by their internal peers around their level. Even google's & microsoft's current CEOs are supported by their group of co-executives and other key players. The fact that both have agreeable personalities is not a mistake! They both need to keep that balance to stay in power, and that means not destroying or disrupting your peer's current positions. Everything is effectively decided by informal committee.

Founders are special, because they are not beholden to this social support network to stay in power and founders have a mythos that socially supports their actions beyond their pure power position. The only others they are beholden too are their co-founders, and in some cases major investor groups. This gives them the ability to disregard this social balance because they are not dependent on it to stay on power. Their power source is external to the organization, while everyone else is internal to it.

This gives them a very special "do something" ability that nobody else has. It can lead to failures (zuck & occulus, snapchat spectacles) or successes (steve jobs, gemini AI), but either way, it allows them to actually "do something".