In my humble opinion stack ranking was meant to create a clear process by which to measure people relative to their roles and each other. (I'm not defending the practice, just stating purpose.) Instead it created selective pressure that measured how well you could game the process to appear successful and push down the ranking of everyone else for yourself and your employees.

During the stack ranking heyday there was a manager who spent his year compiling a list of mistakes by other teams. When it came to year end reviews anyone asking about the ranking of this manager's people ended up deflected with questions about their own team members. People learned to just leave this manager's rankings alone and work around him. He was wildly successful, getting promoted early and often before leaving the company to go start a recruiting firm which allegedly applies some sort of AI principles to picking good candidates.