I would say, it depends on the codebase and documentation. Taking up a abandoned mess of undocumented spaghetti code? No thank you. And most "open sourced" repositories are like this.

But the ones that have at least rudimentary documenation, something a new maintainer has something to work with - those are the few ones, that might be picked up by some community. Rare, yes - because there is not much fun in writing documentation on your personal pet project in your free time. But it might be still worth it.