Most of those have been fixed a long time ago, but we simply don't have the resources to triage them.

This effort we start is in no small part to decrease the number of issues that will be created by empowering the users to unblock themselves* and solidifying Yarn's codebase.

* You wouldn't believe the number of issues that are simply about things working as they should - we can't really blame their authors because it can be quite hard to find the right paragraph in the documentation, but it's extremely taxing on a small team. Similarly, we often have issues created against older releases, or without reproducible test case.

And npm had 2166 at the time they archived their old GitHub repo, moved over to npm-cli (with issues disabled), and have all their issues in a Discourse forum, so you can't get an overall count, nor any connection to PRs and commits.

So I'm not sure you can glean too much from just looking at an issue count in isolation.