[Supermancho]

> Tracking output metrics (including LOC, # of PRs, velocity points) doesn't help you identify or fix poor tooling, culture, or processes.

So what? The question isn't "what helps you fix everything?"

The question is "how useful is velocity?"...without qualification as how you quantified the values. Looking deeper, the question naturally progresses to "what is the most useful metric?" or even "what is a useful metric?" in determining performance (a scary thought experiment for most developers).

Narrowing the scope of the analysis is a necessary step in determining value. Let's dispense with the gaming numbers strawmen and refactoring and testing rigor etc etc.

Theoretically, if it's you (alone) on a project and you have no other external signals about how well features are valued, what singular value, over time, would you look at and judge your progress historically? This is the closest you can get to an abstract vision of (personal) performance on a project divested from all other concerns. I can always look at my LoC.