People might be interested in gitless [0], which purports to be "a Git-compatible version control system, that is easy to learn and use". It appears to be built on top of git, using a simplified conceptual model.
I read about it in one of Adrian Colyer's "the morning paper" blog posts from 2016, "What’s wrong with Git? A conceptual design analysis" [1], which summarizes the paper that critiques git and describes gitless. (The link to the paper at the beginning of the post no longer works, but a commenter suggested this [2] instead.)
I should point out that I've never used gitless, and I don't know whether it's still maintained, but if nothing else the critique itself is interesting.
[1] https://blog.acolyer.org/2016/10/24/whats-wrong-with-git-a-c...
[2] https://web.archive.org/web/20131230194321/http://people.csa...