Sure, sometimes I want to work with a WIP commit and then I'm just doing that in git.

I think functionally of the stage is about the UI, so keeping it separate is kind of the point. I find that useful, as I can use both approaches, not sure how its better if jj can just use one?

> to ask why they do this.

This was what I was trying to explain. To me the feature is needing to manually mark every line to be committed. If I need to split the commit I'm already not paying that much attention.