For me, I am and have been using it in two different situations:

• at work, when I was writing tests and documentation for an old numeric library somebody else wrote, and tests for an OS abstraction layer for real-time systems. With git, I used to use worktrees to keep and extend the documentation in another branch. I found that in jujutsu, a worktree was not needed because it was easier/quicker to work on different branches (or series of changes) than in git.

• at home, in two leisure projects written in Guile and Rust. Here, I wanted a clean/tidy history including for the parts that were developed in an experimental manner. With the git CLI, that would have required heavy use of rebase and so on. I would have used the Magit git interface, but most likely I would have avoided most of the tidying up because of the extra effort1. With jujutsu, this was much less effort - it was fun.

Currently, I don't use jujutsu at work because I am taking over an old legacy project from an almost-retired developer and he is still helping me explaining things and looking at his last changes in the maintenance branch. I don't want to burden him with a new tool as his time is very scarce. (But jujutsu is perfect for things like "throwaway refactoring" of legacy code, so I will for sure use it in the future).

BTW, I was using git CLI since 2008 or so, and Emacs/Magit since about 2017, full time. But I often needed to look up more complex git functions in the man pages.