I saw this video few days ago which describes some of the alternative to Git and of course Fossil is one of them. I have used Fossil in some projects and found to be ok. I found Pijul https://pijul.org/ described in this talk to be very interesting. It was discussed on HN before. Source: https://www.youtube.com/watch?v=M4KktA_jbOE
Pijul has always fascinated me. It’s like the holy grail of version control. But for my personal projects, I develop in a straight line anyway, and I’m not in control of what’s used at work, so I’ve never really used it.
Check out https://github.com/martinvonz/jj/. It's highly inspired by Pijul, among VCSes, and uses a git backing store, so you can use it personally and (mostly) seamlessly interact with any git-only team.