The problem appeared when people like I started basing our workflow on it ^_^. There are a few good books[1] and tutorials[2] out there, but I totally agree that the official documentation is only useful as a technical reference.
[1] Mastering Git, https://www.packtpub.com/product/mastering-git/9781783553754 [2] Atlassian Git tutorials, https://www.atlassian.com/git/tutorials
git was originally explicitly a VCS core for anyone to build on. Remember the "plumbing vs porcelain" days? I do.
And after 18 years what have the "adults" done in the meantime? Come at them sideways for having the gall to release an unrefined tool that got popular?
The core of git is cool. Few simple commands, easy to use. The remaining stuff is something only a mother could love.