sshfs is nice. but in case of network upsss the mount point may stall. -> error
backup to the same fs isn’t a good idea anyway. (rm -rf /* 
)
look at restic.
restic is a simple yet powerfull backup tool.
restic can back up to aws s3, openstack, google, … data are encrypted. should be save. and you don’t need a server.
https://restic.readthedocs.io/en/latest/030_preparing_a_new_repo.html
in combination with rclone you have a lot more targets.
https://restic.readthedocs.io/en/latest/030_preparing_a_new_repo.html#other-services-via-rclone
https://rclone.org
sample resitc script: Rsync to cloud storage for backups?