Very true.

A pattern I've seen when relationship between employee and superior goes south is similar to disfavored step-child:

They get less praise for doing well, and more blame for any mistake.

This tends to escalate over time, and very often the employee's performance will degrade (since they won't get any credit anyway) which escalates the situation.

Often they "patch things up" a few times, but if they really aren't compatible, it's just a tenuous forced balance that will eventually break and plunge the relationship to even deeper depths.

Of course in this situation, all performance reviews for the employee are anywhere from slightly to heavily distorted in their disfavor.

This will always result in one of them eventually leaving the team, typically the employee.

It sucks that it’s not commonplace for managers to be accountable to their reports.

Google has kinda structured things in this way, at least as far as I can tell from the outside. Managers can’t decide who is hired or fired and performance reviews are done by committee.

Seems pretty egalitarian but I’m told that even still, politics becomes an issue.

I haven't worked at Google, but from what I've heard, politics becomes an even bigger issue. If you're only worried about your boss (and your boss's boss, presumably), that's like two people to impress. If you're going to get graded by a committee, not only do you have to do good work, you also have to make sure everybody on the committee knows you're doing good work; and you have to fight people on your team to get the opportunities to do visible good works.

This is all true, and usually means the report would do much better in a different management situation. Unfortunately for the report, it's more convenient to reassign (or fire) one report than bring in a new manager (who may have trouble working with all the other reports). Fair? Not traditionally. But in a capitalist sense, yes, it is.