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.
Not working on it (yet), but I wish the jj <-> github story was a little more ergonomic.
Additionally, I am really missing support for stacked diffs, ie, easily pushing a number of commits into one PR on github each such that they all show their incremental diff.
ezyang's gh stack was pretty useful, if a little bit fragile [0]
and graphite.dev is also very nice, but paid software with a strong VC based motivation to become everyone's everything instead of a nice focused tool.
https://github.com/LucioFranco/jj-spr is one way to get stacked diffs on GitHub with jj, but also GitHub has at least claimed on X that native stacked diffs is coming so we'll see how that goes!