I think you may be reading something into the term “adversarial” that isn’t there. A relationship can be both adversarial and cooperative at the same time, that is just the nature of human behavior.

My personal take on things is that if you don’t recognize the adversarial part of the employer/employee relationship, then you will suffer for it. It’s more healthy to recognize where parties have competing interests, and it’s unhealthy to ignore them.

I’d also say that the people who can ignore the adversarial aspects of employment can only do so because of a fair bit of privilege. For example, people will throw around the saying here that “HR is an advocate for the company, not the employee,” but many of us will never really have to deal with HR in a way where it really matters.