No, it really isn’t. I have used git since shortly after it was first released and I’ve written a git implementation.
I switched to jj in one day. And the amount of git arcana I have to keep in working memory is now basically nil. My VCS now works in almost a 1:1 mapping with how my brain wants to interact with my repo rather than having to go through a translation layer.
If you understand what git commands are doing, what jj does is essentially trivial to add to your mental model.
I also get the benefit of being able to use workflows that I always want to use in git but which are an enormous pain in practice. And I get access to wildly powerful new workflows I didn’t even consider because they would be outlandish in git.