Once you actually start using it it is dead simple and integrates extremely well with stuff you (might) already do.
I have a Git repo which contains my dotfiles + every “large” (annexed) file I want to back up under my home directory.
Git annex automatically tracks where all annexed files are, how many copies there are on various repos, etc.
I add and modify files using mostly standard git commands.
It supports pretty much anything as a “remote”.
It’s extremely simple to restore backups locally or remotely.
Basically Git annex is the Git of backup solutions IME, allowing you extreme flexibility to do exactly what you want, provided you take the time to learn how to do what you want.