Over the internet for file sync. Desktop devices.

They are and are actually enforced by the EU: https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32004L0022

I’m still fascinated that “calibrated” glasses are not more common. In Germany, you won’t get any beer without any markings where the volume is indicated.

https://de.m.wikipedia.org/wiki/Füllstrich#/media/Datei%3AWeizenbier.jpg

I heard good things about Newsblur. They offer a service and an open source version for self hosting

https://github.com/samuelclay/NewsBlur

This is a great hint, thank you. I just discovered that the official restic docs recommend this method too

Thank you!

https://restic.readthedocs.io/en/latest/080_examples.html

This might be a good idea. It would only work for files that allow read access for the group, but that should be fine

Restic uses smart Delta backups, creating a tar before the restic process would defeat the purpose. The permission issue is the same, as I need to have access to the Files either way.