Strategies for using Unraid as a backup target for my family's computers – and what that mean for off-site backups

Using Unraid as a backup target for the family's computers are one of the primary reasons I got a home server. We already do backups (three Macbooks, one Win11) to the cloud using Arq Backup. But I would like to add a local target to the mix, where the increased throughput would allow for more frequent backups.

There are two conceptually different options:

1. Using a backup tools like Arq Backup or Restic that does incremental, encrypted, and compressed backups.

2. Using Rclone, Rsync, or something similar to keep a mountable copy of each computers home folder on the server.

My initial thought was that the second option made most sense. On our home network, there is no need for encryption on the backup target, and having the files in a mountable share would make it easy for the other family members to restore individual files.

But as I was doing research on wether Rclone or Rsync would be best for this, reading up on their settings, I realised that a "real" backup solution like Arq has a big plus: Built in versioning. It seems like that's possible to achieve with both Rclone and Rsync as well, with "archive folders" where deleted or modified files are stored. But with a complex folder structure and no easy way to configure rules for retention, the benefits I had in mind with "plain" folders are as big as I thought, and perhaps restoring older versions is actually easier using Arqs GUI compared to finding the right folder.

So I'm know leaning towards Arq for local backups – but would like to hear what more seasoned Unraid users experiences/advice are.

But going with Arq for local backups might also mean I have to rethink my approach to off-site backups: Here my plan was to take care of that from the server instead of from each computer, using Restic/Duplicati/Duplicacy/Kopia (interested in input for this decision as well!) to do off-site backups in a more centralised way. But if our computers' backups are stored as encrypted blobs, I guess these backup tools will have a hard time to work efficiently, with deduplication, versioning, etc.

So, if I go with Computer -> Arq -> Unraid for local backups, should the computers manage their cloud backups individually and backups done from Unraid to the cloud only take care of data that is exclusive to the server?