Activity != Quality
So you need a library for doing foo. No problem – you hop over to GitHub and you find FooX and FooY. FooX hasn't had a commit for over a year, it has no open pull requests and generally no activity to be seen. On the other hand FooY had a commit just last week, and there are a bunch of pending pull requests, open issues, and associated activity. Which library are you inclined to choose?