Every single place that I've worked at that's introduced any sort of goal based metrics has immediately become, in real terms, unproductive and unsatisfying organizations. As soon as you have a metric, even self-defined, that you will be graded on you optimize for it as the ol' Law dictates.

As soon as that happened support of existing services crumbles. Innovation tanks because risk means you might miss the target. It means the best engineers no longer mentor or build team based expertise. It means everyone becomes solos to hit their number or target and everything else falls away.

I'm sympathetic toward the want to measure employee quality but by doing that you tend to only punish the underperforming engineers, regardless of reasons, rather than rewarding the best engineers or an increase in quality of engineering. It creates hostility when one person's metric may be impacted by another person or org within the company. It sabotages everything the powers that be claim to care about.