The problems with jj that led me to abandon are:

- All of everything good about it breaks down the instant you want to share work with the outside world. It's git on the backend! Except there isn't any concept of a remote jj so you have to go through the painful steps of manually naming commits, pushing, pulling, then manually advancing the current working point to match. And in doing so, you lose almost everything that gives it value in the first place - the elegant multi branch handling, anonymous commits, the evolog. Even if you want to work on the same project on two machines your only choice for this is without breaking everything via git is to rsync the folder. Yes, you can write alias to do all this like git. I might as well use git if I can't use the nice features.

- All files automatically committed is great until you accidentally put a secret in an unignored file in the repository folder. And then there is no way to ensure that it's purged (unlike in git) - the community response as far as I can tell is "Don't do this, never put a file that isn't in gitignore".

- And adding to .gitignore fails if you ever want to wind back in history - if you go back before a file was added to .gitignore, then whoops now it isn't ignored, is all part of your immutable history, and disappears if you ever switch off of that new commit state.