NNGroup published this useful summary about the way focusing on metrics can be detrimental to teams, organizations, and their customers, especially when they're funneled into a single metric like in the North Star framework.
NN starts by arguing that the common saying "what can't be measured can't be managed" is a misquote, and that the actual quote is the polar opposite: "“It is wrong to suppose that if you can’t measure it, you can’t manage it – a costly myth.”
Campbell’s law states that the more important a metric is in social decision making, the more likely it is to be manipulated.
There's a similar saying by another social scientist:
Godhart’s Law states that “When a measure becomes a target, it ceases to be a good measure”
Both statements argue that single metrics can't substitute for holistic, complicated human behavior.
When humans are put in a situation where a metric is of high importance, they are very likely to modify their behavior in order to improve the metric, but this doesn't mean they'll act in a way that corresponds to the underlying intention or problem the metric is trying to solve.
There are many examples of this: