I don't think you should make the metrics the end all be all (Goodhart's law), but that graph is certainly helpful if you can figure out who might be doing literally NOTHING for hours on end vs. someone who is productive at some level. All trying to "figure it out" at that point as a manager is just trying to cut through someone's bullshit when the data is right there.
Maybe it's more like 90% of the cases those metrics shouldn't be used to measure anything, but they can certainly point out "smoke" where there might be someone struggling and then you can be an actual manager and figure it out case by case.