Backing up files with rsync --fake-super is great for security: All file types and attributes can be backed up without the need for root access on the destination. This can also be used to reduce the impact of ransomware attacks.
However, recovering those attributes requires copying the entire file tree with rsync again, which can be a lengthy and space-consuming process.
If the backup is going to a secondary, cold-standby, machine, reactivating the data will lose precious time in an emergency. fake-super to the rescue: It resets the file attributes, permissions, and types (symlink, socket, character/block device, named pipe, …) in-place, speeding up the recovery process.