The main advantage is the content addressable part. Existing overlay filesystems only handle the overlay aspect, and then tools like docker/containerd attempt t

The main advantage is the content addressable part. Existing overlay filesystems only handle the overlay aspect, and then tools like docker/containerd attempt to reuse layers efficiently, but it's not perfect. The same files from two different layers may have the same content, but it's still stored twice because the layers are the "unit" of storage roughly speaking. By making a single filesystem which handles both content addressability and the overlay aspect, you can avoid duplicating files that are the same, but in different layers.