A lot of the blame for how bad the ranking system is belongs to the workforce at large. I've been a supervisor for a number of years and the majority of feedback provided is total garbage. Nothing of substance. Nothing meaningful. Nothing actionable. If you feel like your supervisor isn't giving you helpful feedback it is very likely your knowlegable others are providing total garbage nonsense. A large number of people don't even reply to the request. I have to hunt them down and ask them to fill it out. Many say things like I don't really know them well or can we do this over the phone. It isn't the career connect system that is the problem keeping you from getting meaningful feedback it is people who aren't willing to dedicate time to providing thoughtful feedback.
You might not like it, but @1bop+1lCZVqiu is telling the truth.