[skoczymroczny]

Because such abstraction will always be leaky and when things break, you will need to get down to the git level anyway. Also it would be harder to find contributors to your project if you don't use git directly, or you'd have to maintain two sets of instructions, for git users and for easy-git-whatever users.

It's kind of like wondering, "why hasn't anyone come up with a sane language that people can use in place of Javascript (of course the same language would just use old Javascript under the hood". Sure, there is TypeScript and like, and it solves many problems, but it introduces others.

[irrational]

Sure you would need somebody on the team who can get down to the git level when things go wrong, but do all the rest of the team members have to work at that level? Not everyone has to be a DBA to work with a database. It seems that we could have a level of abstraction for the majority of use cases.