It can't be helped. With higher versions of Android, the full backup option has ended. You can back up installed apps and various settings. Use Google backup, or use various apps with backup functionality. The current recovery backup is incomplete and can only revert to an identical system and carries the risk of a failed recovery.
The main problem is that you cannot overwrite, edit, or otherwise modify system files. Even with root privileges. Recovery then by normal means is unknown. However, some specialized applications can handle backup and restore.