This reads a bit weird so I'm interpreting it as "what kind of workplace causes you to not trust your colleagues to be reasonable?"
Lots. There are many places where developers will play outright power games in order to posture and preserve their position. The PR is a big spot where this can shine through in black/white. As a manager, I really have to police GitHub/GitLab/Bitbucket to ensure that this isn't happening.
I've had juniors, equals, and seniors hold up months worth of work for arbitrary reasons, purposefully pushing past deadlines. Some even admit to it behind closed doors/in meetings. Toxic work places surely exist.
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To be clear, I am 100% in support of peer reviewed work as a SWE (PR's, external auditing, etc)... I'm just expressing that I've experienced the check/balances of peer reviewed work weaponized, typically to feign importance or as an unfair attempt to advance someone's career. I feel like it's just the human condition that some people will just take advantage.