So number of daily/weekly downloads on PyPI/npm/etc?
All these things are a proxy for popularity and that is a valuable metric. I have seen projects with amazing code quality but if they are not maintained eventually they stop working due to updates to dependencies, external APIs, runtime environment, etc. And I have see projects with meh code quality but so popular that every quirk and weird issue had a known workaround. Take ffmpeg for example: its code is.. arcane. But would you choose a random video transcoder written in JavaScript just due to the beautiful code that was last updated in 2012?
It is fine if a dependency hasn't been updated in years, if the number of dependent projects hasn't gone down. Especially if no issues are getting created. Particularly with cargo or npm type package managers where a dependency may do one small thing that never needs to change. Time since last update can be a good thing, it doesn't always mean abandoned.
All these things are a proxy for popularity and that is a valuable metric. I have seen projects with amazing code quality but if they are not maintained eventually they stop working due to updates to dependencies, external APIs, runtime environment, etc. And I have see projects with meh code quality but so popular that every quirk and weird issue had a known workaround. Take ffmpeg for example: its code is.. arcane. But would you choose a random video transcoder written in JavaScript just due to the beautiful code that was last updated in 2012?