Maintainer's activity in GitHub issue is also a good metric.
I imagine that I am not the only one.
Edit: https://github.com/blaise-io/contribution
For example.. I guess that maybe gaming the system really is required if thats a 'good measure'.
"Library/repository activity has little to do with usability, or quality. Some things are more or less finished and correct."
Some software just does what it is supposed to and doesn't need to change, and this is OK, and I have no idea why this fact infuriates some people.