I was testing Restic for the same reason: backup valuable photos and videos and free up space for more. Although I’ve found it suit my workflow and help me in other backup needs very well. For those reasons, I was very happy with it. Well, until I read “it sounds like restic is not the right tool for this”.
Moments ago, I was looking for a way to mark a backup as non-deletable, protected or something similar. That’s how I ended up in this post and just found out the same very owner says Restic is not for what I wanted.
I think there is still a way to use it for photo archive: tags. Tags could give semantic meaning to snapshots, at least for me. Something like: “photos”, “protected” “2017”. What do you think? Another tool is still a better idea?