From 1945 to about 2000, academia in the western world was slowly growing. That made the pool of positions not-quite-zero-sum, and way too many people went into it expecting a much more genial environment.
In other words, the academics do not grow the pool through their own actions, as in private business. They are forever reliant on the kindness of strangers.
We have acquired a couple such companies and the people that survived that environment are some of the most toxic players you ever meet. They are also really good at the game so they immediately rise to power and begin to devour their next victim.