It might count, but it is easy with git as well, what is the feature in jj that makes this easier? Switching branches and pushing changes to remotes is the core feature of git and in my opinion really easy so I'm curious how jj improves on it.

rebases don't lose branches and jj absorb trivially squashes changes to the correct head (or leaves changes alone if it can't find where to squash).

is it possible in git? yeah, I've done it; there's a reason I haven't done it more than a few times with git, though. ergonomics matter.