Just to play devils advocate:
If you have two engineers and one consistently completes 10 points a sprint and the other only completes 2 points a sprint, does that not tell you something about the output of those engineers?
If you have two engineers and one consistently completes 10 points a sprint and the other only completes 2 points a sprint, does that not tell you something about the output of those engineers?
Or as I usually put it: Statistics/charts are for asking questions, not answering them.
Low point stories that take a lot of time are often coordination tasks, and for people who are good at heads down programming, that can be their kryptonite.
It's also possible that Mr 2 Points is not getting fed stories that they could weave into the blocking points of their highest priority task effectively. He is spending a lot of time working on untracked tasks or sneakily working on stories halfway down the backlog. And they can't do it in the open because someone is engaging in Efficiency Theater: we are so far behind on some milestone that the optics of anyone working on anything except that milestone are terrible.
Nevermind that the next milestone needs them and we will be having this Death March repeat again in three months because of it.