A killer feature rustic has over restic is built-in support for .gitignore files. So all your dependencies and build output is automatically ignored in your backups.
At first I thought that sounded great, but then I realized that that would exclude files that I want to be backed up, like `dir-locals-2.el`, which should be excluded from git, but should also be backed up. There doesn't seem to be a great solution to that in general.