Git is designed for an environment where there are multiple canonical trunks. RedHats kernel is equally a master as SuSe's. So you are maintaining various tips in a semi-synchronized manner. In most projects there is a single repository branch that is the true branch (with perhaps a few tags for LTR) that represents the project. For that reason a lot of Git's mechanisms are unneeded complexity.

The killer features of Git is GitHub, and to a lesser degree local commits (after all, Mercurial has that too).

"One click" fork + "one click" pull request are its killer features.