Yes, at the moment it does not. But a well factored system is important for gaining future benefits. For example, I work at a startup that is building jj related tooling, and that the git stuff is separated out cleanly is what enables us to build better things than if it were so tied to git.

To complete the analogy, given that we haven't launched, yes, this is a theoretical benefit for now. But that doesn't mean it's useless. jj is still pre-1.0 software, there's a lot more work to do, and more interesting things coming down the pipeline. That matters, even if it's not relevant to every potential user just yet.