Comment by waboremo

Those are the biggest aspects, but the private aspect is actually an important part of why many open source projects are using it. They don't really want to be having those sort of conversations in github issues or the discussions page or anywhere indexable.

Like getting on a call with a coworker or a collaborator on the project. You can technically record it or leave it open to the public, but most people do not because they just see it as not "informing the public" worthy.