Extreme ownership is not about the pressure of having to deal with "lives on the line".
It is primarily about owning responsibility yourself, and not externalizing blame. Even CEO and CTOs are prone to deflecting blame when there's politics and external parties involved.
All of the case studies show how managers suffer from defense mechanisms and logical fallacies that are harmful rather than helpful.
It also talks about the dangers of operating in a high complexity environment and the need to develop an understandable and legible method of communication.
* He says that leaders aren’t trusted implicitly in the Seal teams either, btw, and it's part of the job of the leader to build rapport with their teams, sell them on the plan, and make sure everyone understands the higher intent, if the team is really to be effective rather than dysfunctional. (this comes later in the book).
The war stories are what folks seem to focus on here, but I feel those are there mostly for entertainment, in addition to an example of the underlying value it's trying to demonstrate.
That said, the book really boils down to continual repetition of a few core points over and over. That may be necessary to drive the relatively few points home, with even fewer actually changing their behavior.
This is deliberately not an academic-level treatise on leadership. It is a challenge to accept the most fundamental challenges of responsibility - how many managers have you met which fail to do that?