I don't have experience with Jujutsu, but I always have the same problem with these alternative frontends, which is that I'd still want to be proficient with the original. If you need to look up how to fix something or you want to help others in your team or you want to script something, then the language to speak is simply the Git CLI.

And I don't feel like I even use the Git CLI enough where a different tool could be so much better that it's worth learning both.
Obviously, your priorities may differ, but yeah, that's just always the reason for me why I prefer the Git CLI, even if it were objectively more difficult to use.

I use plain git when a project wants to use some tool that itself calls git commands that modify the repo state. You can use a colocated repo in this case (where jj and git commands both work) and nothing will break, but it can mess up your graph, creating duplicate commits which you then have to fix. I’ve seen this with Gentoo’s pkgdev for example.

Git blame and some other graph operations are also just faster right now which is why I sometimes use them in large repos over jj’s equivalent.