Yes, a full image backup is best of course. A dietpi-backup onto another drive, or even the same, is simpler to setup as regular task, and allows as well to restore kernel and boot configs e.g., when broken.
or whatever the drive is named . And then, try to mount and check its /boot directory.
More like a GUI for rsync with some wrapping features. rpi-clone clones a disk, dietpi-backup copies the files within the filesystem, excluding partitioning, bootloader etc. Files can be restored from a running system, a disk clone/image not, but from an external system instead.
Actually doing more regular a dietpi-backup (which doesn’t take so much time and writes, as it is incremental), and less regular a full disk clone/image, either via something like rpi-clone or manually from an external system, is a good combination.