Maybe for a local system will do, but for a server its not really a good solution. Any file may depend on any other file and rsync is time consuming. Therefor, some files may ( and will ) change during the rsync process ( aka: file1 is copied, file2 is copied and until rsync will reach file5, file1 is changed ). This will leave you with a dependency disaster when you will need to use that backup.
To avoid this disaster, a snapshot based backup will do the job, because the system will get "froze" before the backup process starts and get it "unfreeze" when the backup process finishes, so all the files are consistent.